xHCI: Clear PLC in xhci_bus_resume()

This patch clears PORT_PLC if xhci_bus_resume() resumes a previous suspended
port, because if a port transition from U3 to U0 state, it will report a
port link state change, and software should clear the corresponding PLC bit.

It also uses hcd->speed to check if a port is a USB2 protocol port.

The patch fixes the issue that USB keyboard can not wakeup system from
hibernation.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index a78f2eb..73f75d2 100644 (file)
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -777,7 +777,7 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
                if (t1 != t2)
                        xhci_writel(xhci, t2, port_array[port_index]);
 
-               if (DEV_HIGHSPEED(t1)) {
+               if (hcd->speed != HCD_USB3) {
                        /* enable remote wake up for USB 2.0 */
                        u32 __iomem *addr;
                        u32 tmp;
@@ -866,6 +866,21 @@ int xhci_bus_resume(struct usb_hcd *hcd)
                                temp |= PORT_LINK_STROBE | XDEV_U0;
                                xhci_writel(xhci, temp, port_array[port_index]);
                        }
+                       /* wait for the port to enter U0 and report port link
+                        * state change.
+                        */
+                       spin_unlock_irqrestore(&xhci->lock, flags);
+                       msleep(20);
+                       spin_lock_irqsave(&xhci->lock, flags);
+
+                       /* Clear PLC */
+                       temp = xhci_readl(xhci, port_array[port_index]);
+                       if (temp & PORT_PLC) {
+                               temp = xhci_port_state_to_neutral(temp);
+                               temp |= PORT_PLC;
+                               xhci_writel(xhci, temp, port_array[port_index]);
+                       }
+
                        slot_id = xhci_find_slot_id_by_port(hcd,
                                        xhci, port_index + 1);
                        if (slot_id)
@@ -873,7 +888,7 @@ int xhci_bus_resume(struct usb_hcd *hcd)
                } else
                        xhci_writel(xhci, temp, port_array[port_index]);
 
-               if (DEV_HIGHSPEED(temp)) {
+               if (hcd->speed != HCD_USB3) {
                        /* disable remote wake up for USB 2.0 */
                        u32 __iomem *addr;
                        u32 tmp;