[PATCH v2] usb: host: xhci: wait USB2 port enter suspend for bus suspend

[Li Jun <jun.li@nxp.com>]

If the connected USB2 device wakeup is not enabled/supported, the link
state may still be U0 when do xhci bus suspend, after we suspend ports
in U0, we need give time to device to enter suspend before do further
suspend operations (e.g. system suspend), otherwise we may enter system
suspend with link state at U0.

Signed-off-by: Li Jun <jun.li@nxp.com>
---
Change for v2:
-Use bus_state->bus_suspended to check if any port may be at U0.

 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 c799ca5..74c497f 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;
 }
 
-- 
2.7.4