path: root/drivers/usb/core/hub.c
diff options
authorAndiry Xu <andiry.xu@gmail.com>2012-05-05 00:50:10 +0800
committerSarah Sharp <sarah.a.sharp@linux.intel.com>2012-05-17 10:36:57 -0700
commitc3e751e4f4754793bb52bd5ae30e9cc027edbb12 (patch)
tree93fbd40123a934b70371932c2d5e9e3773f42eef /drivers/usb/core/hub.c
parent1530bbc6272d9da1e39ef8e06190d42c13a02733 (diff)
usbcore: enable USB2 LPM if port suspend fails
USB2 LPM is disabled when device begin to suspend and enabled after device is resumed. That's because USB spec does not define the transition from U1/U2 state to U3 state. If usb_port_suspend() fails, usb_port_resume() is never called, and USB2 LPM is disabled in this situation. Enable USB2 LPM if port suspend fails. This patch should be backported to kernels as old as 3.2, that contain the commit 65580b4321eb36f16ae8b5987bfa1bb948fc5112 "xHCI: set USB2 hardware LPM". Signed-off-by: Andiry Xu <andiry.xu@gmail.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/usb/core/hub.c')
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index ec6c97dadbe..c8e0704c6e5 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2499,6 +2499,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
NULL, 0,
+ /* Try to enable USB2 hardware LPM again */
+ if (udev->usb2_hw_lpm_capable == 1)
+ usb_set_usb2_hardware_lpm(udev, 1);
/* System sleep transitions should never fail */
if (!PMSG_IS_AUTO(msg))
status = 0;