Before a driver is probed, we want to disable USB 3.0 Link Power Management (LPM), in case the driver needs hub-initiated LPM disabled. After the probe finishes, we want to attempt to re-enable LPM, order to balance the LPM ref count. When a probe fails (such as when libusual doesn't want to bind to a USB 3.0 mass storage device), make sure to balance the LPM ref counts by re-enabling LPM. This patch 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@xxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/usb/core/driver.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index ddd820d..6056db7 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -367,6 +367,10 @@ static int usb_probe_interface(struct device *dev) intf->condition = USB_INTERFACE_UNBOUND; usb_cancel_queued_reset(intf); + /* If the LPM disable succeeded, balance the ref counts. */ + if (!lpm_disable_error) + usb_unlocked_enable_lpm(udev); + /* Unbound interfaces are always runtime-PM-disabled and -suspended */ if (driver->supports_autosuspend) pm_runtime_disable(dev); -- 1.7.9 -- 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
