diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2012-12-18 15:25:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-11 16:16:01 -0800 |
| commit | 8d8479db3dde3ef7a9bc803e565842764fa21a53 (patch) | |
| tree | 6c4e2b049c675b62be0fd3d65ae606f367dfb56c /drivers/usb/core/generic.c | |
| parent | ece1d77ed73b335319725f1d5ffa72ca3fa9b05c (diff) | |
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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/generic.c')
| -rw-r--r-- | drivers/usb/core/generic.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index eff2010eb63f..271e761f563e 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; } |