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authorAndiry Xu <andiry.xu@gmail.com>2012-05-05 00:50:10 +0800
committerBen Hutchings <ben@decadent.org.uk>2012-05-31 00:43:43 +0100
commitadc4185584c4fd1c057cafe152fc69994a9786e6 (patch)
tree1efa0496fdc0f6643f18a06bdd77ee91764194d5
parent48302fa5e081367809c2c2dd5cb43ef56f89877d (diff)
usbcore: enable USB2 LPM if port suspend fails
commit c3e751e4f4754793bb52bd5ae30e9cc027edbb12 upstream. 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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/usb/core/hub.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 2b0a341c471..52d27ed4ed7 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2420,6 +2420,10 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
NULL, 0,
USB_CTRL_SET_TIMEOUT);
+ /* 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;