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ALSA: usb-audio: Register card at the last interface 

The USB-audio driver matches per interface, and as default, it
registers the card instance at the very first instance.  This can be a
problem for the devices that have multiple interfaces to be probed, as
the udev rule isn't applied properly for the later appearing
interfaces.  Although we introduced the delayed_register option and
the quirks for covering those shortcomings, it's nothing but a
workaround for specific devices.

This patch is an another attempt to fix the problem in a more generic
way.  Now the driver checks the whole USB device descriptor at the
very first time when an interface is attached to a sound card.  It
looks at each matching interface in the descriptor and remembers the
last matching one.  The snd_card_register() is invoked only when this
last interface is probed.

After this change, the quirks for the delayed registration become
superfluous, hence they are removed along with the patch.  OTOH, the
delayed_register option is still kept, as it might be useful for some
corner cases (e.g. a special driver overtakes the interface probe from
the standard driver, and the last interface probe may miss).

Link: https://lore.kernel.org/r/20220904161247.16461-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2022-09-04 18:12:47 +02:00
parent 16c5cde20e
commit 6392dcd1d0
4 changed files with 26 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
sound/usb/card.c
View File

@ -690,7 +690,7 @@ static bool get_alias_id(struct usb_device *dev, unsigned int *id)
return false;
}
static bool check_delayed_register_option(struct snd_usb_audio *chip, int iface)
static int check_delayed_register_option(struct snd_usb_audio *chip)
{
int i;
unsigned int id, inum;
@ -699,14 +699,31 @@ static bool check_delayed_register_option(struct snd_usb_audio *chip, int iface)
if (delayed_register[i] &&
sscanf(delayed_register[i], "%x:%x", &id, &inum) == 2 &&
id == chip->usb_id)
return iface < inum;
return inum;
}
return false;
return -1;
}
static const struct usb_device_id usb_audio_ids[]; /* defined below */
/* look for the last interface that matches with our ids and remember it */
static void find_last_interface(struct snd_usb_audio *chip)
{
struct usb_host_config *config = chip->dev->actconfig;
struct usb_interface *intf;
int i;
if (!config)
return;
for (i = 0; i < config->desc.bNumInterfaces; i++) {
intf = config->interface[i];
if (usb_match_id(intf, usb_audio_ids))
chip->last_iface = intf->altsetting[0].desc.bInterfaceNumber;
}
usb_audio_dbg(chip, "Found last interface = %d\n", chip->last_iface);
}
/* look for the corresponding quirk */
static const struct snd_usb_audio_quirk *
get_alias_quirk(struct usb_device *dev, unsigned int id)
@ -813,6 +830,7 @@ static int usb_audio_probe(struct usb_interface *intf,
err = -ENODEV;
goto __error;
}
find_last_interface(chip);
}
if (chip->num_interfaces >= MAX_CARD_INTERFACES) {
@ -862,11 +880,11 @@ static int usb_audio_probe(struct usb_interface *intf,
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
/* register card if we reach to the last interface or to the specified
* one given via option
*/
if (!snd_usb_registration_quirk(chip, ifnum) &&
!check_delayed_register_option(chip, ifnum)) {
if (check_delayed_register_option(chip) == ifnum ||
chip->last_iface == ifnum) {
err = snd_card_register(chip->card);
if (err < 0)
goto __error;

42
sound/usb/quirks.c
View File

@ -2030,48 +2030,6 @@ void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
}
}
/*
* registration quirk:
* the registration is skipped if a device matches with the given ID,
* unless the interface reaches to the defined one. This is for delaying
* the registration until the last known interface, so that the card and
* devices appear at the same time.
*/
struct registration_quirk {
unsigned int usb_id; /* composed via USB_ID() */
unsigned int interface; /* the interface to trigger register */
};
#define REG_QUIRK_ENTRY(vendor, product, iface) \
{ .usb_id = USB_ID(vendor, product), .interface = (iface) }
static const struct registration_quirk registration_quirks[] = {
REG_QUIRK_ENTRY(0x0951, 0x16d8, 2), /* Kingston HyperX AMP */
REG_QUIRK_ENTRY(0x0951, 0x16ed, 2), /* Kingston HyperX Cloud Alpha S */
REG_QUIRK_ENTRY(0x0951, 0x16ea, 2), /* Kingston HyperX Cloud Flight S */
REG_QUIRK_ENTRY(0x0ecb, 0x1f46, 2), /* JBL Quantum 600 */
REG_QUIRK_ENTRY(0x0ecb, 0x1f47, 2), /* JBL Quantum 800 */
REG_QUIRK_ENTRY(0x0ecb, 0x1f4c, 2), /* JBL Quantum 400 */
REG_QUIRK_ENTRY(0x0ecb, 0x2039, 2), /* JBL Quantum 400 */
REG_QUIRK_ENTRY(0x0ecb, 0x203c, 2), /* JBL Quantum 600 */
REG_QUIRK_ENTRY(0x0ecb, 0x203e, 2), /* JBL Quantum 800 */
{ 0 } /* terminator */
};
/* return true if skipping registration */
bool snd_usb_registration_quirk(struct snd_usb_audio *chip, int iface)
{
const struct registration_quirk *q;
for (q = registration_quirks; q->usb_id; q++)
if (chip->usb_id == q->usb_id)
return iface < q->interface;
/* Register as normal */
return false;
}
/*
* driver behavior quirk flags
*/

2
sound/usb/quirks.h
View File

@ -48,8 +48,6 @@ void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
struct audioformat *fp,
int stream);
bool snd_usb_registration_quirk(struct snd_usb_audio *chip, int iface);
void snd_usb_init_quirk_flags(struct snd_usb_audio *chip);
#endif /* __USBAUDIO_QUIRKS_H */

1
sound/usb/usbaudio.h
View File

@ -37,6 +37,7 @@ struct snd_usb_audio {
unsigned int quirk_flags;
unsigned int need_delayed_register:1; /* warn for delayed registration */
int num_interfaces;
int last_iface;
int num_suspended_intf;
int sample_rate_read_error;