USB: Fix LPM disable count mismatch on driver unbind.

When a user runs `echo 0 > bConfigurationValue` for a USB 3.0 device,
usb_disable_device() is called.  This function disables all drivers,
deallocates interfaces, and sets the device configuration value to 0
(unconfigured).

With the new scheme to ensure that unconfigured devices have LPM
disabled, usb_disable_device() must call usb_unlocked_disable_lpm() once
it unconfigures the device.

This commit should be backported to kernels as old as 3.5, that contain
the commit 8306095fd2c1100e8244c09bf560f97aca5a311d "USB: Disable USB
3.0 LPM in critical sections."

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 37239048be14ff189108428d6aabd01f9b140d64..c0877b7f505ac3a707f8e381075feaf539253282 100644 (file)
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1174,6 +1174,7 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0)
                        put_device(&dev->actconfig->interface[i]->dev);
                        dev->actconfig->interface[i] = NULL;
                }
+               usb_unlocked_disable_lpm(dev);
                dev->actconfig = NULL;
                if (dev->state == USB_STATE_CONFIGURED)
                        usb_set_device_state(dev, USB_STATE_ADDRESS);