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authorAndiry Xu <andiry.xu@amd.com>2011-08-03 16:46:49 +0800
committerGreg Kroah-Hartman <gregkh@suse.de>2011-10-03 11:39:52 -0700
commitdbb2e00b9a1774d1e740d952e2e9e87a178866bd (patch)
treeee7843f1974f5544195013e3cf918e39d1cdd451 /drivers/usb/host/xhci-ring.c
parenteff529629832537fbd6837912add0c4a8cb7d585 (diff)
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xHCI: report USB2 port in resuming as suspend
commit 8a8ff2f9399b23b968901f585ccb5a70a537c5ae upstream. When a USB2 port initiate a remote wakeup, software shall ensure that resume is signaled for at least 20ms, and then write '0' to the PLS field. According to this, xhci driver do the following things: 1. When receive a remote wakeup event in irq_handler, set the resume_done value as jiffies + 20ms, and modify rh_timer to poll root hub status at that time; 2. When receive a GetPortStatus request, if the jiffies is after the resume_done value, clear the resume signal and resume_done. However, if usb_port_resume() is called before the rh_timer triggered, it will indicate the port as Suspend Cleared and skip the clear resume signal part. The device will fail the usb_get_status request in finish_port_resume(), and usbcore will try a reset-resume instead. Device will work OK after reset-resume, but resume_done value is not cleared in this case, and xhci_bus_suspend() will fail because when it finds a non-zero resume_done value, it will regard the port as resuming and return -EBUSY. This causes issue on some platforms that the system fail to suspend after remote wakeup from suspend by USB2 devices connected to xHCI port. To fix this issue, report the port status as suspend if the resume is signaling less that 20ms, and usb_port_resume() will wait 25ms and check port status again, so xHCI driver can clear the resume signaling and resume_done value. This should be backported to kernels as old as 2.6.37. Signed-off-by: Andiry Xu <andiry.xu@amd.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
0 files changed, 0 insertions, 0 deletions