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>

1 files changed, 17 insertions, 2 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index a78f2ebd11b7..73f75d26436c 100644
--- 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;