[PATCH] 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>
---
 drivers/usb/host/xhci-hub.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index c799ca5..1e054d0 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1598,6 +1598,7 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 	struct xhci_hub *rhub;
 	struct xhci_port **ports;
 	u32 portsc_buf[USB_MAXCHILDREN];
+	bool wait_port_enter_u3 = false;
 	bool wake_enabled;
 
 	rhub = xhci_get_rhub(hcd);
@@ -1706,12 +1707,17 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 				xhci_stop_device(xhci, slot_id, 1);
 				spin_lock_irqsave(&xhci->lock, flags);
 			}
+			wait_port_enter_u3 = true;
 		}
 		writel(portsc_buf[port_index], ports[port_index]->addr);
 	}
 	hcd->state = HC_STATE_SUSPENDED;
 	bus_state->next_statechange = jiffies + msecs_to_jiffies(10);
 	spin_unlock_irqrestore(&xhci->lock, flags);
+
+	if (wait_port_enter_u3)
+		usleep_range(5000, 10000);
+
 	return 0;
 }
 
-- 
2.7.4