From: Li Jun jun.li@nxp.com
If a USB2 device wakeup is not enabled/supported the link state may still be in U0 in xhci_bus_suspend(), where it's then manually put to suspended U3 state.
Just as with selective suspend the device needs time to enter U3 suspend before continuing with further suspend operations (e.g. system suspend), otherwise we may enter system suspend with link state in U0.
[commit message rewording -Mathias] Cc: stable@vger.kernel.org Signed-off-by: Li Jun jun.li@nxp.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/host/xhci-hub.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index c799ca5361d4..74c497fd3476 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1712,6 +1712,10 @@ int xhci_bus_suspend(struct usb_hcd *hcd) hcd->state = HC_STATE_SUSPENDED; bus_state->next_statechange = jiffies + msecs_to_jiffies(10); spin_unlock_irqrestore(&xhci->lock, flags); + + if (bus_state->bus_suspended) + usleep_range(5000, 10000); + return 0; }