From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Sarah Sharp Subject: [ 47/85] USB: Enable LPM after a failed probe. Date: Thu, 25 Oct 2012 17:06:05 -0700 Message-Id: <20121026000035.851998438@linuxfoundation.org> In-Reply-To: <20121026000031.107227138@linuxfoundation.org> References: <20121026000031.107227138@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sarah Sharp commit d01f87c0ffa96cb44faa78710711eb6e974b891c upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/driver.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -372,6 +372,10 @@ static int usb_probe_interface(struct de 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);