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 sysfs interface &
the device descriptor dump compute the value on their own.
Cc: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
v1…v2: - moved usb_get_max_power() to usb.h
- removed the multiplier argument from the macro and implemented
show_bMaxPower from scratch
drivers/usb/core/devices.c | 13 ++++++++++---
drivers/usb/core/generic.c | 2 +-
drivers/usb/core/hub.c | 2 +-
drivers/usb/core/message.c | 2 +-
drivers/usb/core/sysfs.c | 37 ++++++++++++++++++++++++++++---------
drivers/usb/core/usb.h | 9 +++++++++
6 files changed, 50 insertions(+), 15 deletions(-)
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index cbacea9..e33224e 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -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;
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index eff2010..271e761 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -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;
}
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index a815fd2..4735425 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4152,7 +4152,7 @@ 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
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 131f736..444d30e 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -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",
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 818e4a0..472fcb1 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -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 +28,37 @@ 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, "%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;
+ unsigned multiplier;
-usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
-usb_actconfig_attr(bmAttributes, 1, "%2x\n")
-usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")
+ udev = to_usb_device(dev);
+ if (udev->speed == USB_SPEED_SUPER)
+ multiplier = 8;
+ else
+ multiplier = 2;
+
+ actconfig = udev->actconfig;
+ if (!actconfig)
+ return 0;
+ return sprintf(buf, "%dmA\n", actconfig->desc.bMaxPower * multiplier);
+}
+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 +75,7 @@ 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,
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 1c528c1..fb7d8fc 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -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,
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
