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Commit 8d8479db authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Greg Kroah-Hartman
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usb/core: consider link speed while looking at bMaxPower 



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: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ece1d77e

drivers/usb/core/devices.c

+10 −3
Original line number Diff line number Diff line
@@ -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;

drivers/usb/core/generic.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

		}

drivers/usb/core/hub.c

+1 −1
Original line number Diff line number Diff line
@@ -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

drivers/usb/core/message.c

+1 −1
Original line number Diff line number Diff line
@@ -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",

drivers/usb/core/sysfs.c

+22 −9
Original line number Diff line number Diff line
@@ -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)			\

#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,