linux-stable/sound/usb/card.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* (Tentative) USB Audio Driver for ALSA
*
* Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
*
* Many codes borrowed from audio.c by
* Alan Cox (alan@lxorguk.ukuu.org.uk)
* Thomas Sailer (sailer@ife.ee.ethz.ch)
*
* Audio Class 3.0 support by Ruslan Bilovol <ruslan.bilovol@gmail.com>
*
* NOTES:
*
* - the linked URBs would be preferred but not used so far because of
* the instability of unlinking.
* - type II is not supported properly. there is no device which supports
* this type *correctly*. SB extigy looks as if it supports, but it's
* indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
*/
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/usb.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>
#include <linux/usb/audio-v3.h>
#include <linux/module.h>
#include <sound/control.h>
#include <sound/core.h>
#include <sound/info.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include "usbaudio.h"
#include "card.h"
#include "midi.h"
#include "mixer.h"
#include "proc.h"
#include "quirks.h"
#include "endpoint.h"
#include "helper.h"
#include "debug.h"
#include "pcm.h"
#include "format.h"
#include "power.h"
#include "stream.h"
media: sound/usb: Use Media Controller API to share media resources Media Device Allocator API to allows multiple drivers share a media device. This API solves a very common use-case for media devices where one physical device (an USB stick) provides both audio and video. When such media device exposes a standard USB Audio class, a proprietary Video class, two or more independent drivers will share a single physical USB bridge. In such cases, it is necessary to coordinate access to the shared resource. Using this API, drivers can allocate a media device with the shared struct device as the key. Once the media device is allocated by a driver, other drivers can get a reference to it. The media device is released when all the references are released. Change the ALSA driver to use the Media Controller API to share media resources with DVB, and V4L2 drivers on a AU0828 media device. The Media Controller specific initialization is done after sound card is registered. ALSA creates Media interface and entity function graph nodes for Control, Mixer, PCM Playback, and PCM Capture devices. snd_usb_hw_params() will call Media Controller enable source handler interface to request the media resource. If resource request is granted, it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is returned. Media specific cleanup is done in usb_audio_disconnect(). Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Shuah Khan <shuah@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-04-02 00:40:22 +00:00
#include "media.h"
MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("USB Audio");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
/* Vendor/product IDs for this card */
static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
static bool ignore_ctl_error;
static bool autoclock = true;
static char *quirk_alias[SNDRV_CARDS];
static char *delayed_register[SNDRV_CARDS];
bool snd_usb_use_vmalloc = true;
bool snd_usb_skip_validation;
module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
module_param_array(id, charp, NULL, 0444);
MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
module_param_array(vid, int, NULL, 0444);
MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
module_param_array(pid, int, NULL, 0444);
MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
module_param_array(device_setup, int, NULL, 0444);
MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
module_param(ignore_ctl_error, bool, 0444);
MODULE_PARM_DESC(ignore_ctl_error,
"Ignore errors from USB controller for mixer interfaces.");
module_param(autoclock, bool, 0444);
MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
module_param_array(quirk_alias, charp, NULL, 0444);
MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");
module_param_array(delayed_register, charp, NULL, 0444);
MODULE_PARM_DESC(delayed_register, "Quirk for delayed registration, given by id:iface, e.g. 0123abcd:4.");
module_param_named(use_vmalloc, snd_usb_use_vmalloc, bool, 0444);
MODULE_PARM_DESC(use_vmalloc, "Use vmalloc for PCM intermediate buffers (default: yes).");
module_param_named(skip_validation, snd_usb_skip_validation, bool, 0444);
MODULE_PARM_DESC(skip_validation, "Skip unit descriptor validation (default: no).");
/*
* we keep the snd_usb_audio_t instances by ourselves for merging
* the all interfaces on the same card as one sound device.
*/
static DEFINE_MUTEX(register_mutex);
static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
static struct usb_driver usb_audio_driver;
/*
* disconnect streams
* called from usb_audio_disconnect()
*/
static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
{
int idx;
struct snd_usb_substream *subs;
for (idx = 0; idx < 2; idx++) {
subs = &as->substream[idx];
if (!subs->num_formats)
continue;
subs->interface = -1;
subs->data_endpoint = NULL;
subs->sync_endpoint = NULL;
}
}
static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
{
struct usb_device *dev = chip->dev;
struct usb_host_interface *alts;
struct usb_interface_descriptor *altsd;
struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
if (!iface) {
dev_err(&dev->dev, "%u:%d : does not exist\n",
ctrlif, interface);
return -EINVAL;
}
alts = &iface->altsetting[0];
altsd = get_iface_desc(alts);
/*
* Android with both accessory and audio interfaces enabled gets the
* interface numbers wrong.
*/
if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
interface == 0 &&
altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
interface = 2;
iface = usb_ifnum_to_if(dev, interface);
if (!iface)
return -EINVAL;
alts = &iface->altsetting[0];
altsd = get_iface_desc(alts);
}
if (usb_interface_claimed(iface)) {
dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
ctrlif, interface);
return -EINVAL;
}
if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
int err = __snd_usbmidi_create(chip->card, iface,
&chip->midi_list, NULL,
chip->usb_id);
if (err < 0) {
dev_err(&dev->dev,
"%u:%d: cannot create sequencer device\n",
ctrlif, interface);
return -EINVAL;
}
usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
return 0;
}
if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
dev_dbg(&dev->dev,
"%u:%d: skipping non-supported interface %d\n",
ctrlif, interface, altsd->bInterfaceClass);
/* skip non-supported classes */
return -EINVAL;
}
if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
dev_err(&dev->dev, "low speed audio streaming not supported\n");
return -EINVAL;
}
if (! snd_usb_parse_audio_interface(chip, interface)) {
usb_set_interface(dev, interface, 0); /* reset the current interface */
usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
}
return 0;
}
/*
* parse audio control descriptor and create pcm/midi streams
*/
static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
{
struct usb_device *dev = chip->dev;
struct usb_host_interface *host_iface;
struct usb_interface_descriptor *altsd;
int i, protocol;
/* find audiocontrol interface */
host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
altsd = get_iface_desc(host_iface);
protocol = altsd->bInterfaceProtocol;
switch (protocol) {
default:
dev_warn(&dev->dev,
"unknown interface protocol %#02x, assuming v1\n",
protocol);
/* fall through */
case UAC_VERSION_1: {
struct uac1_ac_header_descriptor *h1;
int rest_bytes;
h1 = snd_usb_find_csint_desc(host_iface->extra,
host_iface->extralen,
NULL, UAC_HEADER);
if (!h1 || h1->bLength < sizeof(*h1)) {
dev_err(&dev->dev, "cannot find UAC_HEADER\n");
return -EINVAL;
}
rest_bytes = (void *)(host_iface->extra +
host_iface->extralen) - (void *)h1;
/* just to be sure -- this shouldn't hit at all */
if (rest_bytes <= 0) {
dev_err(&dev->dev, "invalid control header\n");
return -EINVAL;
}
ALSA: usb-audio: Check out-of-bounds access by corrupted buffer descriptor When a USB-audio device receives a maliciously adjusted or corrupted buffer descriptor, the USB-audio driver may access an out-of-bounce value at its parser. This was detected by syzkaller, something like: BUG: KASAN: slab-out-of-bounds in usb_audio_probe+0x27b2/0x2ab0 Read of size 1 at addr ffff88006b83a9e8 by task kworker/0:1/24 CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.0-rc1-42251-gebb2c2437d80 #224 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 print_address_description+0x78/0x280 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 kasan_report+0x22f/0x340 mm/kasan/report.c:409 __asan_report_load1_noabort+0x19/0x20 mm/kasan/report.c:427 snd_usb_create_streams sound/usb/card.c:248 usb_audio_probe+0x27b2/0x2ab0 sound/usb/card.c:605 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 This patch adds the checks of out-of-bounce accesses at appropriate places and bails out when it goes out of the given buffer. Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-22 14:18:53 +00:00
if (rest_bytes < sizeof(*h1)) {
dev_err(&dev->dev, "too short v1 buffer descriptor\n");
return -EINVAL;
}
if (!h1->bInCollection) {
dev_info(&dev->dev, "skipping empty audio interface (v1)\n");
return -EINVAL;
}
ALSA: usb-audio: Check out-of-bounds access by corrupted buffer descriptor When a USB-audio device receives a maliciously adjusted or corrupted buffer descriptor, the USB-audio driver may access an out-of-bounce value at its parser. This was detected by syzkaller, something like: BUG: KASAN: slab-out-of-bounds in usb_audio_probe+0x27b2/0x2ab0 Read of size 1 at addr ffff88006b83a9e8 by task kworker/0:1/24 CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.0-rc1-42251-gebb2c2437d80 #224 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 print_address_description+0x78/0x280 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 kasan_report+0x22f/0x340 mm/kasan/report.c:409 __asan_report_load1_noabort+0x19/0x20 mm/kasan/report.c:427 snd_usb_create_streams sound/usb/card.c:248 usb_audio_probe+0x27b2/0x2ab0 sound/usb/card.c:605 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 This patch adds the checks of out-of-bounce accesses at appropriate places and bails out when it goes out of the given buffer. Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-09-22 14:18:53 +00:00
if (rest_bytes < h1->bLength) {
dev_err(&dev->dev, "invalid buffer length (v1)\n");
return -EINVAL;
}
if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
dev_err(&dev->dev, "invalid UAC_HEADER (v1)\n");
return -EINVAL;
}
for (i = 0; i < h1->bInCollection; i++)
snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
break;
}
case UAC_VERSION_2:
case UAC_VERSION_3: {
struct usb_interface_assoc_descriptor *assoc =
usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
if (!assoc) {
/*
* Firmware writers cannot count to three. So to find
* the IAD on the NuForce UDH-100, also check the next
* interface.
*/
struct usb_interface *iface =
usb_ifnum_to_if(dev, ctrlif + 1);
if (iface &&
iface->intf_assoc &&
iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
assoc = iface->intf_assoc;
}
if (!assoc) {
dev_err(&dev->dev, "Audio class v2/v3 interfaces need an interface association\n");
return -EINVAL;
}
if (protocol == UAC_VERSION_3) {
int badd = assoc->bFunctionSubClass;
if (badd != UAC3_FUNCTION_SUBCLASS_FULL_ADC_3_0 &&
(badd < UAC3_FUNCTION_SUBCLASS_GENERIC_IO ||
badd > UAC3_FUNCTION_SUBCLASS_SPEAKERPHONE)) {
dev_err(&dev->dev,
"Unsupported UAC3 BADD profile\n");
return -EINVAL;
}
chip->badd_profile = badd;
}
for (i = 0; i < assoc->bInterfaceCount; i++) {
int intf = assoc->bFirstInterface + i;
if (intf != ctrlif)
snd_usb_create_stream(chip, ctrlif, intf);
}
break;
}
}
return 0;
}
/*
* free the chip instance
*
* here we have to do not much, since pcm and controls are already freed
*
*/
static void snd_usb_audio_free(struct snd_card *card)
{
struct snd_usb_audio *chip = card->private_data;
struct snd_usb_endpoint *ep, *n;
list_for_each_entry_safe(ep, n, &chip->ep_list, list)
snd_usb_endpoint_free(ep);
mutex_destroy(&chip->mutex);
ALSA: usb-audio: Fix use-after-free of usb_device at disconnect The usb-audio driver implements the deferred device disconnection for the device in use. In this mode, the disconnection callback returns immediately while the actual ALSA card object removal happens later when all files get closed. As Shuah reported, this code flow, however, leads to a use-after-free, detected by KASAN: BUG: KASAN: use-after-free in snd_usb_audio_free+0x134/0x160 [snd_usb_audio] at addr ffff8801c863ce10 Write of size 8 by task pulseaudio/2244 Call Trace: [<ffffffff81b31473>] dump_stack+0x67/0x94 [<ffffffff81564ef1>] kasan_object_err+0x21/0x70 [<ffffffff8156518a>] kasan_report_error+0x1fa/0x4e0 [<ffffffff81564ad7>] ? kasan_slab_free+0x87/0xb0 [<ffffffff81565733>] __asan_report_store8_noabort+0x43/0x50 [<ffffffffa0fc0f54>] ? snd_usb_audio_free+0x134/0x160 [snd_usb_audio] [<ffffffffa0fc0f54>] snd_usb_audio_free+0x134/0x160 [snd_usb_audio] [<ffffffffa0fc0fb1>] snd_usb_audio_dev_free+0x31/0x40 [snd_usb_audio] [<ffffffff8243c78a>] __snd_device_free+0x12a/0x210 [<ffffffff8243d1f5>] snd_device_free_all+0x85/0xd0 [<ffffffff8242cae4>] release_card_device+0x34/0x130 [<ffffffff81ef1846>] device_release+0x76/0x1e0 [<ffffffff81b37ad7>] kobject_release+0x107/0x370 ..... Object at ffff8801c863cc80, in cache kmalloc-2048 size: 2048 Allocated: [<ffffffff810804eb>] save_stack_trace+0x2b/0x50 [<ffffffff81564296>] save_stack+0x46/0xd0 [<ffffffff8156450d>] kasan_kmalloc+0xad/0xe0 [<ffffffff81560d1a>] kmem_cache_alloc_trace+0xfa/0x240 [<ffffffff8214ea47>] usb_alloc_dev+0x57/0xc90 [<ffffffff8216349d>] hub_event+0xf1d/0x35f0 .... Freed: [<ffffffff810804eb>] save_stack_trace+0x2b/0x50 [<ffffffff81564296>] save_stack+0x46/0xd0 [<ffffffff81564ac1>] kasan_slab_free+0x71/0xb0 [<ffffffff81560929>] kfree+0xd9/0x280 [<ffffffff8214de6e>] usb_release_dev+0xde/0x110 [<ffffffff81ef1846>] device_release+0x76/0x1e0 .... It's the code trying to clear drvdata of the assigned usb_device where the usb_device itself was already released in usb_release_dev() after the disconnect callback. This patch fixes it by checking whether the code path is via the disconnect callback, i.e. chip->shutdown flag is set. Fixes: 79289e24194a ('ALSA: usb-audio: Refer to chip->usb_id for quirks...') Reported-and-tested-by: Shuah Khan <shuahkh@osg.samsung.com> Cc: <stable@vger.kernel.org> # v4.6+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-11-14 20:46:47 +00:00
if (!atomic_read(&chip->shutdown))
dev_set_drvdata(&chip->dev->dev, NULL);
}
static void usb_audio_make_shortname(struct usb_device *dev,
struct snd_usb_audio *chip,
const struct snd_usb_audio_quirk *quirk)
{
struct snd_card *card = chip->card;
if (quirk && quirk->product_name && *quirk->product_name) {
strlcpy(card->shortname, quirk->product_name,
sizeof(card->shortname));
return;
}
/* retrieve the device string as shortname */
if (!dev->descriptor.iProduct ||
usb_string(dev, dev->descriptor.iProduct,
card->shortname, sizeof(card->shortname)) <= 0) {
/* no name available from anywhere, so use ID */
sprintf(card->shortname, "USB Device %#04x:%#04x",
USB_ID_VENDOR(chip->usb_id),
USB_ID_PRODUCT(chip->usb_id));
}
strim(card->shortname);
}
static void usb_audio_make_longname(struct usb_device *dev,
struct snd_usb_audio *chip,
const struct snd_usb_audio_quirk *quirk)
{
struct snd_card *card = chip->card;
int len;
/* shortcut - if any pre-defined string is given, use it */
if (quirk && quirk->profile_name && *quirk->profile_name) {
strlcpy(card->longname, quirk->profile_name,
sizeof(card->longname));
return;
}
if (quirk && quirk->vendor_name && *quirk->vendor_name) {
len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
} else {
/* retrieve the vendor and device strings as longname */
if (dev->descriptor.iManufacturer)
len = usb_string(dev, dev->descriptor.iManufacturer,
card->longname, sizeof(card->longname));
else
len = 0;
/* we don't really care if there isn't any vendor string */
}
if (len > 0) {
strim(card->longname);
if (*card->longname)
strlcat(card->longname, " ", sizeof(card->longname));
}
strlcat(card->longname, card->shortname, sizeof(card->longname));
len = strlcat(card->longname, " at ", sizeof(card->longname));
if (len < sizeof(card->longname))
usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
switch (snd_usb_get_speed(dev)) {
case USB_SPEED_LOW:
strlcat(card->longname, ", low speed", sizeof(card->longname));
break;
case USB_SPEED_FULL:
strlcat(card->longname, ", full speed", sizeof(card->longname));
break;
case USB_SPEED_HIGH:
strlcat(card->longname, ", high speed", sizeof(card->longname));
break;
case USB_SPEED_SUPER:
strlcat(card->longname, ", super speed", sizeof(card->longname));
break;
case USB_SPEED_SUPER_PLUS:
strlcat(card->longname, ", super speed plus", sizeof(card->longname));
break;
default:
break;
}
}
/*
* create a chip instance and set its names.
*/
static int snd_usb_audio_create(struct usb_interface *intf,
struct usb_device *dev, int idx,
const struct snd_usb_audio_quirk *quirk,
unsigned int usb_id,
struct snd_usb_audio **rchip)
{
struct snd_card *card;
struct snd_usb_audio *chip;
int err;
char component[14];
*rchip = NULL;
switch (snd_usb_get_speed(dev)) {
case USB_SPEED_LOW:
case USB_SPEED_FULL:
case USB_SPEED_HIGH:
case USB_SPEED_WIRELESS:
case USB_SPEED_SUPER:
case USB_SPEED_SUPER_PLUS:
break;
default:
dev_err(&dev->dev, "unknown device speed %d\n", snd_usb_get_speed(dev));
return -ENXIO;
}
err = snd_card_new(&intf->dev, index[idx], id[idx], THIS_MODULE,
sizeof(*chip), &card);
if (err < 0) {
dev_err(&dev->dev, "cannot create card instance %d\n", idx);
return err;
}
chip = card->private_data;
mutex_init(&chip->mutex);
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
init_waitqueue_head(&chip->shutdown_wait);
chip->index = idx;
chip->dev = dev;
chip->card = card;
chip->setup = device_setup[idx];
chip->autoclock = autoclock;
atomic_set(&chip->active, 1); /* avoid autopm during probing */
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
atomic_set(&chip->usage_count, 0);
atomic_set(&chip->shutdown, 0);
chip->usb_id = usb_id;
INIT_LIST_HEAD(&chip->pcm_list);
INIT_LIST_HEAD(&chip->ep_list);
INIT_LIST_HEAD(&chip->midi_list);
INIT_LIST_HEAD(&chip->mixer_list);
card->private_free = snd_usb_audio_free;
strcpy(card->driver, "USB-Audio");
sprintf(component, "USB%04x:%04x",
USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
snd_component_add(card, component);
usb_audio_make_shortname(dev, chip, quirk);
usb_audio_make_longname(dev, chip, quirk);
snd_usb_audio_create_proc(chip);
*rchip = chip;
return 0;
}
/* look for a matching quirk alias id */
static bool get_alias_id(struct usb_device *dev, unsigned int *id)
{
int i;
unsigned int src, dst;
for (i = 0; i < ARRAY_SIZE(quirk_alias); i++) {
if (!quirk_alias[i] ||
sscanf(quirk_alias[i], "%x:%x", &src, &dst) != 2 ||
src != *id)
continue;
dev_info(&dev->dev,
"device (%04x:%04x): applying quirk alias %04x:%04x\n",
USB_ID_VENDOR(*id), USB_ID_PRODUCT(*id),
USB_ID_VENDOR(dst), USB_ID_PRODUCT(dst));
*id = dst;
return true;
}
return false;
}
static bool check_delayed_register_option(struct snd_usb_audio *chip, int iface)
{
int i;
unsigned int id, inum;
for (i = 0; i < ARRAY_SIZE(delayed_register); i++) {
if (delayed_register[i] &&
sscanf(delayed_register[i], "%x:%x", &id, &inum) == 2 &&
id == chip->usb_id)
return inum != iface;
}
return false;
}
static const struct usb_device_id usb_audio_ids[]; /* defined below */
/* look for the corresponding quirk */
static const struct snd_usb_audio_quirk *
get_alias_quirk(struct usb_device *dev, unsigned int id)
{
const struct usb_device_id *p;
for (p = usb_audio_ids; p->match_flags; p++) {
/* FIXME: this checks only vendor:product pair in the list */
if ((p->match_flags & USB_DEVICE_ID_MATCH_DEVICE) ==
USB_DEVICE_ID_MATCH_DEVICE &&
p->idVendor == USB_ID_VENDOR(id) &&
p->idProduct == USB_ID_PRODUCT(id))
return (const struct snd_usb_audio_quirk *)p->driver_info;
}
return NULL;
}
/*
* probe the active usb device
*
* note that this can be called multiple times per a device, when it
* includes multiple audio control interfaces.
*
* thus we check the usb device pointer and creates the card instance
* only at the first time. the successive calls of this function will
* append the pcm interface to the corresponding card.
*/
static int usb_audio_probe(struct usb_interface *intf,
const struct usb_device_id *usb_id)
{
struct usb_device *dev = interface_to_usbdev(intf);
const struct snd_usb_audio_quirk *quirk =
(const struct snd_usb_audio_quirk *)usb_id->driver_info;
struct snd_usb_audio *chip;
int i, err;
struct usb_host_interface *alts;
int ifnum;
u32 id;
alts = &intf->altsetting[0];
ifnum = get_iface_desc(alts)->bInterfaceNumber;
id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
le16_to_cpu(dev->descriptor.idProduct));
if (get_alias_id(dev, &id))
quirk = get_alias_quirk(dev, id);
if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
return -ENXIO;
err = snd_usb_apply_boot_quirk(dev, intf, quirk, id);
if (err < 0)
return err;
/*
* found a config. now register to ALSA
*/
/* check whether it's already registered */
chip = NULL;
mutex_lock(&register_mutex);
for (i = 0; i < SNDRV_CARDS; i++) {
if (usb_chip[i] && usb_chip[i]->dev == dev) {
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
if (atomic_read(&usb_chip[i]->shutdown)) {
dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
err = -EIO;
goto __error;
}
chip = usb_chip[i];
atomic_inc(&chip->active); /* avoid autopm */
break;
}
}
if (! chip) {
err = snd_usb_apply_boot_quirk_once(dev, intf, quirk, id);
if (err < 0)
goto __error;
/* it's a fresh one.
* now look for an empty slot and create a new card instance
*/
for (i = 0; i < SNDRV_CARDS; i++)
if (!usb_chip[i] &&
(vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
(pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
if (enable[i]) {
err = snd_usb_audio_create(intf, dev, i, quirk,
id, &chip);
if (err < 0)
goto __error;
chip->pm_intf = intf;
break;
} else if (vid[i] != -1 || pid[i] != -1) {
dev_info(&dev->dev,
"device (%04x:%04x) is disabled\n",
USB_ID_VENDOR(id),
USB_ID_PRODUCT(id));
err = -ENOENT;
goto __error;
}
}
if (!chip) {
dev_err(&dev->dev, "no available usb audio device\n");
err = -ENODEV;
goto __error;
}
}
dev_set_drvdata(&dev->dev, chip);
/*
* For devices with more than one control interface, we assume the
* first contains the audio controls. We might need a more specific
* check here in the future.
*/
if (!chip->ctrl_intf)
chip->ctrl_intf = alts;
chip->txfr_quirk = 0;
err = 1; /* continue */
if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
/* need some special handlings */
err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
if (err < 0)
goto __error;
}
if (err > 0) {
/* create normal USB audio interfaces */
err = snd_usb_create_streams(chip, ifnum);
if (err < 0)
goto __error;
err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
if (err < 0)
goto __error;
}
if (chip->need_delayed_register) {
dev_info(&dev->dev,
"Found post-registration device assignment: %08x:%02x\n",
chip->usb_id, ifnum);
chip->need_delayed_register = false; /* clear again */
}
/* we are allowed to call snd_card_register() many times, but first
* check to see if a device needs to skip it or do anything special
*/
if (!snd_usb_registration_quirk(chip, ifnum) &&
!check_delayed_register_option(chip, ifnum)) {
err = snd_card_register(chip->card);
if (err < 0)
goto __error;
}
media: sound/usb: Use Media Controller API to share media resources Media Device Allocator API to allows multiple drivers share a media device. This API solves a very common use-case for media devices where one physical device (an USB stick) provides both audio and video. When such media device exposes a standard USB Audio class, a proprietary Video class, two or more independent drivers will share a single physical USB bridge. In such cases, it is necessary to coordinate access to the shared resource. Using this API, drivers can allocate a media device with the shared struct device as the key. Once the media device is allocated by a driver, other drivers can get a reference to it. The media device is released when all the references are released. Change the ALSA driver to use the Media Controller API to share media resources with DVB, and V4L2 drivers on a AU0828 media device. The Media Controller specific initialization is done after sound card is registered. ALSA creates Media interface and entity function graph nodes for Control, Mixer, PCM Playback, and PCM Capture devices. snd_usb_hw_params() will call Media Controller enable source handler interface to request the media resource. If resource request is granted, it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is returned. Media specific cleanup is done in usb_audio_disconnect(). Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Shuah Khan <shuah@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-04-02 00:40:22 +00:00
if (quirk && quirk->shares_media_device) {
/* don't want to fail when snd_media_device_create() fails */
snd_media_device_create(chip, intf);
}
usb_chip[chip->index] = chip;
chip->num_interfaces++;
usb_set_intfdata(intf, chip);
atomic_dec(&chip->active);
mutex_unlock(&register_mutex);
return 0;
__error:
if (chip) {
/* chip->active is inside the chip->card object,
* decrement before memory is possibly returned.
*/
atomic_dec(&chip->active);
if (!chip->num_interfaces)
snd_card_free(chip->card);
}
mutex_unlock(&register_mutex);
return err;
}
/*
* we need to take care of counter, since disconnection can be called also
* many times as well as usb_audio_probe().
*/
static void usb_audio_disconnect(struct usb_interface *intf)
{
struct snd_usb_audio *chip = usb_get_intfdata(intf);
struct snd_card *card;
struct list_head *p;
if (chip == (void *)-1L)
return;
card = chip->card;
mutex_lock(&register_mutex);
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
if (atomic_inc_return(&chip->shutdown) == 1) {
struct snd_usb_stream *as;
struct snd_usb_endpoint *ep;
struct usb_mixer_interface *mixer;
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
/* wait until all pending tasks done;
* they are protected by snd_usb_lock_shutdown()
*/
wait_event(chip->shutdown_wait,
!atomic_read(&chip->usage_count));
snd_card_disconnect(card);
/* release the pcm resources */
list_for_each_entry(as, &chip->pcm_list, list) {
snd_usb_stream_disconnect(as);
}
/* release the endpoint resources */
list_for_each_entry(ep, &chip->ep_list, list) {
snd_usb_endpoint_release(ep);
}
/* release the midi resources */
list_for_each(p, &chip->midi_list) {
snd_usbmidi_disconnect(p);
}
media: sound/usb: Use Media Controller API to share media resources Media Device Allocator API to allows multiple drivers share a media device. This API solves a very common use-case for media devices where one physical device (an USB stick) provides both audio and video. When such media device exposes a standard USB Audio class, a proprietary Video class, two or more independent drivers will share a single physical USB bridge. In such cases, it is necessary to coordinate access to the shared resource. Using this API, drivers can allocate a media device with the shared struct device as the key. Once the media device is allocated by a driver, other drivers can get a reference to it. The media device is released when all the references are released. Change the ALSA driver to use the Media Controller API to share media resources with DVB, and V4L2 drivers on a AU0828 media device. The Media Controller specific initialization is done after sound card is registered. ALSA creates Media interface and entity function graph nodes for Control, Mixer, PCM Playback, and PCM Capture devices. snd_usb_hw_params() will call Media Controller enable source handler interface to request the media resource. If resource request is granted, it will release it from snd_usb_hw_free(). If resource is busy, -EBUSY is returned. Media specific cleanup is done in usb_audio_disconnect(). Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Shuah Khan <shuah@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-04-02 00:40:22 +00:00
/*
* Nice to check quirk && quirk->shares_media_device and
* then call the snd_media_device_delete(). Don't have
* access to the quirk here. snd_media_device_delete()
* accesses mixer_list
*/
snd_media_device_delete(chip);
/* release mixer resources */
list_for_each_entry(mixer, &chip->mixer_list, list) {
snd_usb_mixer_disconnect(mixer);
}
ALSA: usb-audio: Fix device_del() sysfs warnings at disconnect Some USB-audio devices show weird sysfs warnings at disconnecting the devices, e.g. usb 1-3: USB disconnect, device number 3 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180() sysfs group ffffffff8183df40 not found for kobject 'midiC1D0' Call Trace: [<ffffffff814a3e38>] ? dump_stack+0x49/0x71 [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0 [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50 [<ffffffff813521e9>] ? device_del+0x39/0x180 [<ffffffff81352339>] ? device_unregister+0x9/0x20 [<ffffffff81352384>] ? device_destroy+0x34/0x40 [<ffffffffa00ba29f>] ? snd_unregister_device+0x7f/0xd0 [snd] [<ffffffffa025124e>] ? snd_rawmidi_dev_disconnect+0xce/0x100 [snd_rawmidi] [<ffffffffa00c0192>] ? snd_device_disconnect+0x62/0x90 [snd] [<ffffffffa00c025c>] ? snd_device_disconnect_all+0x3c/0x60 [snd] [<ffffffffa00bb574>] ? snd_card_disconnect+0x124/0x1a0 [snd] [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio] [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore] [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0 [<ffffffff81355485>] ? device_release_driver+0x25/0x40 [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130 [<ffffffff813522b9>] ? device_del+0x109/0x180 [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore] [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore] [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore] [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80 [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0 [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0 [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore] [<ffffffff8105973e>] ? kthread+0xce/0xf0 [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0 [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0 ---[ end trace 40b1928d1136b91e ]--- This comes from the fact that usb-audio driver may receive the disconnect callback multiple times, per each usb interface. When a device has both audio and midi interfaces, it gets called twice, and currently the driver tries to release resources at the last call. At this point, the first parent interface has been already deleted, thus deleting a child of the first parent hits such a warning. For fixing this problem, we need to call snd_card_disconnect() and cancel pending operations at the very first disconnect while the release of the whole objects waits until the last disconnect call. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=80931 Reported-and-tested-by: Tomas Gayoso <tgayoso@gmail.com> Reported-and-tested-by: Chris J Arges <chris.j.arges@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-05 14:08:49 +00:00
}
chip->num_interfaces--;
if (chip->num_interfaces <= 0) {
usb_chip[chip->index] = NULL;
mutex_unlock(&register_mutex);
snd_card_free_when_closed(card);
} else {
mutex_unlock(&register_mutex);
}
}
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
/* lock the shutdown (disconnect) task and autoresume */
int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
{
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
int err;
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
atomic_inc(&chip->usage_count);
if (atomic_read(&chip->shutdown)) {
err = -EIO;
goto error;
}
err = snd_usb_autoresume(chip);
if (err < 0)
goto error;
return 0;
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
error:
if (atomic_dec_and_test(&chip->usage_count))
wake_up(&chip->shutdown_wait);
return err;
}
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
/* autosuspend and unlock the shutdown */
void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
{
snd_usb_autosuspend(chip);
if (atomic_dec_and_test(&chip->usage_count))
wake_up(&chip->shutdown_wait);
}
#ifdef CONFIG_PM
int snd_usb_autoresume(struct snd_usb_audio *chip)
{
if (atomic_read(&chip->shutdown))
return -EIO;
if (atomic_inc_return(&chip->active) == 1)
return usb_autopm_get_interface(chip->pm_intf);
return 0;
}
void snd_usb_autosuspend(struct snd_usb_audio *chip)
{
ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect ALSA PCM may still have a leftover instance after disconnection and it delays its release. The problem is that the PCM close code path of USB-audio driver has a call of snd_usb_autosuspend(). This involves with the call of usb_autopm_put_interface() and it may lead to a kernel Oops due to the NULL object like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000190 IP: [<ffffffff815ae7ef>] usb_autopm_put_interface+0xf/0x30 PGD 0 Call Trace: [<ffffffff8173bd94>] snd_usb_autosuspend+0x14/0x20 [<ffffffff817461bc>] snd_usb_pcm_close.isra.14+0x5c/0x90 [<ffffffff8174621f>] snd_usb_playback_close+0xf/0x20 [<ffffffff816ef58a>] snd_pcm_release_substream.part.36+0x3a/0x90 [<ffffffff816ef6b3>] snd_pcm_release+0xa3/0xb0 [<ffffffff816debb0>] snd_disconnect_release+0xd0/0xe0 [<ffffffff8114d417>] __fput+0x97/0x1d0 [<ffffffff8114d589>] ____fput+0x9/0x10 [<ffffffff8109e452>] task_work_run+0x72/0x90 [<ffffffff81088510>] do_exit+0x280/0xa80 [<ffffffff8108996a>] do_group_exit+0x3a/0xa0 [<ffffffff8109261f>] get_signal+0x1df/0x540 [<ffffffff81040903>] do_signal+0x23/0x620 [<ffffffff8114c128>] ? do_readv_writev+0x128/0x200 [<ffffffff810012e1>] prepare_exit_to_usermode+0x91/0xd0 [<ffffffff810013ba>] syscall_return_slowpath+0x9a/0x120 [<ffffffff817587cd>] ? __sys_recvmsg+0x5d/0x70 [<ffffffff810d2765>] ? ktime_get_ts64+0x45/0xe0 [<ffffffff8115dea0>] ? SyS_poll+0x60/0xf0 [<ffffffff818d2327>] int_ret_from_sys_call+0x25/0x8f We have already a check of disconnection in snd_usb_autoresume(), but the check is missing its counterpart. The fix is just to put the same check in snd_usb_autosuspend(), too. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109431 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-12 13:03:33 +00:00
if (atomic_read(&chip->shutdown))
return;
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
if (atomic_dec_and_test(&chip->active))
usb_autopm_put_interface(chip->pm_intf);
}
static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
{
struct snd_usb_audio *chip = usb_get_intfdata(intf);
struct snd_usb_stream *as;
struct usb_mixer_interface *mixer;
struct list_head *p;
if (chip == (void *)-1L)
return 0;
chip->autosuspended = !!PMSG_IS_AUTO(message);
if (!chip->autosuspended)
snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
if (!chip->num_suspended_intf++) {
list_for_each_entry(as, &chip->pcm_list, list) {
snd_usb_pcm_suspend(as);
as->substream[0].need_setup_ep =
as->substream[1].need_setup_ep = true;
}
list_for_each(p, &chip->midi_list)
snd_usbmidi_suspend(p);
list_for_each_entry(mixer, &chip->mixer_list, list)
snd_usb_mixer_suspend(mixer);
}
return 0;
}
static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
{
struct snd_usb_audio *chip = usb_get_intfdata(intf);
struct snd_usb_stream *as;
struct usb_mixer_interface *mixer;
struct list_head *p;
int err = 0;
if (chip == (void *)-1L)
return 0;
if (--chip->num_suspended_intf)
return 0;
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
atomic_inc(&chip->active); /* avoid autopm */
list_for_each_entry(as, &chip->pcm_list, list) {
err = snd_usb_pcm_resume(as);
if (err < 0)
goto err_out;
}
/*
* ALSA leaves material resumption to user space
* we just notify and restart the mixers
*/
list_for_each_entry(mixer, &chip->mixer_list, list) {
err = snd_usb_mixer_resume(mixer, reset_resume);
if (err < 0)
goto err_out;
}
list_for_each(p, &chip->midi_list) {
snd_usbmidi_resume(p);
}
if (!chip->autosuspended)
snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
chip->autosuspended = 0;
err_out:
ALSA: usb-audio: Avoid nested autoresume calls After the recent fix of runtime PM for USB-audio driver, we got a lockdep warning like: ============================================= [ INFO: possible recursive locking detected ] 4.2.0-rc8+ #61 Not tainted --------------------------------------------- pulseaudio/980 is trying to acquire lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] but task is already holding lock: (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio] This comes from snd_usb_autoresume() invoking down_read() and it's used in a nested way. Although it's basically safe, per se (as these are read locks), it's better to reduce such spurious warnings. The read lock is needed to guarantee the execution of "shutdown" (cleanup at disconnection) task after all concurrent tasks are finished. This can be implemented in another better way. Also, the current check of chip->in_pm isn't good enough for protecting the racy execution of multiple auto-resumes. This patch rewrites the logic of snd_usb_autoresume() & co; namely, - The recursive call of autopm is avoided by the new refcount, chip->active. The chip->in_pm flag is removed accordingly. - Instead of rwsem, another refcount, chip->usage_count, is introduced for tracking the period to delay the shutdown procedure. At the last clear of this refcount, wake_up() to the shutdown waiter is called. - The shutdown flag is replaced with shutdown atomic count; this is for reducing the lock. - Two new helpers are introduced to simplify the management of these refcounts; snd_usb_lock_shutdown() increases the usage_count, checks the shutdown state, and does autoresume. snd_usb_unlock_shutdown() does the opposite. Most of mixer and other codes just need this, and simply returns an error if it receives an error from lock. Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance') Reported-and-tested-by: Alexnader Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-08-25 14:09:00 +00:00
atomic_dec(&chip->active); /* allow autopm after this point */
return err;
}
static int usb_audio_resume(struct usb_interface *intf)
{
return __usb_audio_resume(intf, false);
}
static int usb_audio_reset_resume(struct usb_interface *intf)
{
return __usb_audio_resume(intf, true);
}
#else
#define usb_audio_suspend NULL
#define usb_audio_resume NULL
#define usb_audio_reset_resume NULL
#endif /* CONFIG_PM */
static const struct usb_device_id usb_audio_ids [] = {
#include "quirks-table.h"
{ .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
.bInterfaceClass = USB_CLASS_AUDIO,
.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, usb_audio_ids);
/*
* entry point for linux usb interface
*/
static struct usb_driver usb_audio_driver = {
.name = "snd-usb-audio",
.probe = usb_audio_probe,
.disconnect = usb_audio_disconnect,
.suspend = usb_audio_suspend,
.resume = usb_audio_resume,
.reset_resume = usb_audio_reset_resume,
.id_table = usb_audio_ids,
.supports_autosuspend = 1,
};
module_usb_driver(usb_audio_driver);