From: Sarah Sharp Date: Thu, 4 Oct 2012 16:53:43 +0000 (-0700) Subject: USB: Enable LPM after a failed probe. X-Git-Tag: v3.7-rc2~17^2~34^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d01f87c0ffa96cb44faa78710711eb6e974b891c;p=profile%2Fcommon%2Fkernel-common.git USB: Enable LPM after a failed probe. 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 Cc: stable@vger.kernel.org --- 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);