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usb/core: consider link speed while looking at bMaxPower

Browse source 
The USB 2.0 specification says that bMaxPower is the maximum power
consumption expressed in 2 mA units and the USB 3.0 specification says
that it is expressed in 8 mA units.
This patch adds a helper function usb_get_max_power() which computes the
value based on config & usb_device's speed value. The the device descriptor
dump computes the value on its own.

Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sebastian Andrzej Siewior 2012-12-18 15:25:46 +01:00 committed by Greg Kroah-Hartman
parent ece1d77ed7
commit 8d8479db3d
6 changed files with 44 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
drivers/usb/core/devices.c
View file

@ -316,17 +316,23 @@ static char *usb_dump_iad_descriptor(char *start, char *end,
*/
static char *usb_dump_config_descriptor(char *start, char *end,
const struct usb_config_descriptor *desc,
int active)
int active, int speed)
{
int mul;
if (start > end)
return start;
if (speed == USB_SPEED_SUPER)
mul = 8;
else
mul = 2;
start += sprintf(start, format_config,
/* mark active/actual/current cfg. */
active ? '*' : ' ',
desc->bNumInterfaces,
desc->bConfigurationValue,
desc->bmAttributes,
desc->bMaxPower * 2);
desc->bMaxPower * mul);
return start;
}
@ -342,7 +348,8 @@ static char *usb_dump_config(int speed, char *start, char *end,
if (!config)
/* getting these some in 2.3.7; none in 2.3.6 */
return start + sprintf(start, "(null Cfg. desc.)\n");
start = usb_dump_config_descriptor(start, end, &config->desc, active);
start = usb_dump_config_descriptor(start, end, &config->desc, active,
speed);
for (i = 0; i < USB_MAXIADS; i++) {
if (config->intf_assoc[i] == NULL)
break;

2
drivers/usb/core/generic.c
View file

@ -100,7 +100,7 @@ int usb_choose_configuration(struct usb_device *udev)
*/
/* Rule out configs that draw too much bus current */
if (c->desc.bMaxPower * 2 > udev->bus_mA) {
if (usb_get_max_power(udev, c) > udev->bus_mA) {
insufficient_power++;
continue;
}

2
drivers/usb/core/hub.c
View file

@ -4211,7 +4211,7 @@ hub_power_remaining (struct usb_hub *hub)
/* Unconfigured devices may not use more than 100mA,
* or 8mA for OTG ports */
if (udev->actconfig)
delta = udev->actconfig->desc.bMaxPower * 2;
delta = usb_get_max_power(udev, udev->actconfig);
else if (port1 != udev->bus->otg_port || hdev->parent)
delta = 100;
else

2
drivers/usb/core/message.c
View file

@ -1751,7 +1751,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
}
}
i = dev->bus_mA - cp->desc.bMaxPower * 2;
i = dev->bus_mA - usb_get_max_power(dev, cp);
if (i < 0)
dev_warn(&dev->dev, "new config #%d exceeds power "
"limit by %dmA\n",

31
drivers/usb/core/sysfs.c
View file

@ -17,7 +17,7 @@
#include "usb.h"
/* Active configuration fields */
#define usb_actconfig_show(field, multiplier, format_string) \
#define usb_actconfig_show(field, format_string) \
static ssize_t show_##field(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
@ -28,18 +28,31 @@ static ssize_t show_##field(struct device *dev, \
actconfig = udev->actconfig; \
if (actconfig) \
return sprintf(buf, format_string, \
actconfig->desc.field * multiplier); \
actconfig->desc.field); \
else \
return 0; \
} \
#define usb_actconfig_attr(field, multiplier, format_string) \
usb_actconfig_show(field, multiplier, format_string) \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
#define usb_actconfig_attr(field, format_string) \
usb_actconfig_show(field, format_string) \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
usb_actconfig_attr(bmAttributes, 1, "%2x\n")
usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")
usb_actconfig_attr(bNumInterfaces, "%2d\n")
usb_actconfig_attr(bmAttributes, "%2x\n")
static ssize_t show_bMaxPower(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
struct usb_host_config *actconfig;
udev = to_usb_device(dev);
actconfig = udev->actconfig;
if (!actconfig)
return 0;
return sprintf(buf, "%dmA\n", usb_get_max_power(udev, actconfig));
}
static DEVICE_ATTR(bMaxPower, S_IRUGO, show_bMaxPower, NULL);
static ssize_t show_configuration_string(struct device *dev,
struct device_attribute *attr, char *buf)
@ -56,7 +69,7 @@ static ssize_t show_configuration_string(struct device *dev,
static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
/* configuration value is always present, and r/w */
usb_actconfig_show(bConfigurationValue, 1, "%u\n");
usb_actconfig_show(bConfigurationValue, "%u\n");
static ssize_t
set_bConfigurationValue(struct device *dev, struct device_attribute *attr,

9
drivers/usb/core/usb.h
View file

@ -38,6 +38,15 @@ extern char *usb_cache_string(struct usb_device *udev, int index);
extern int usb_set_configuration(struct usb_device *dev, int configuration);
extern int usb_choose_configuration(struct usb_device *udev);
static inline unsigned usb_get_max_power(struct usb_device *udev,
struct usb_host_config *c)
{
/* SuperSpeed power is in 8 mA units; others are in 2 mA units */
unsigned mul = (udev->speed == USB_SPEED_SUPER ? 8 : 2);
return c->desc.bMaxPower * mul;
}
extern void usb_kick_khubd(struct usb_device *dev);
extern int usb_match_one_id_intf(struct usb_device *dev,
struct usb_host_interface *intf,