1 files changed, 43 insertions, 4 deletions

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 8c8da2d..2f4850f 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -908,6 +908,41 @@ static void xhci_disable_port_wake_on_bits(struct xhci_hcd *xhci)
 	spin_unlock_irqrestore(&xhci->lock, flags);
 }
 
+static bool xhci_pending_portevent(struct xhci_hcd *xhci)
+{
+	struct xhci_port	**ports;
+	int			port_index;
+	u32			status;
+	u32			portsc;
+
+	status = readl(&xhci->op_regs->status);
+	if (status & STS_EINT)
+		return true;
+	/*
+	 * Checking STS_EINT is not enough as there is a lag between a change
+	 * bit being set and the Port Status Change Event that it generated
+	 * being written to the Event Ring. See note in xhci 1.1 section 4.19.2.
+	 */
+
+	port_index = xhci->usb2_rhub.num_ports;
+	ports = xhci->usb2_rhub.ports;
+	while (port_index--) {
+		portsc = readl(ports[port_index]->addr);
+		if (portsc & PORT_CHANGE_MASK ||
+		    (portsc & PORT_PLS_MASK) == XDEV_RESUME)
+			return true;
+	}
+	port_index = xhci->usb3_rhub.num_ports;
+	ports = xhci->usb3_rhub.ports;
+	while (port_index--) {
+		portsc = readl(ports[port_index]->addr);
+		if (portsc & PORT_CHANGE_MASK ||
+		    (portsc & PORT_PLS_MASK) == XDEV_RESUME)
+			return true;
+	}
+	return false;
+}
+
 /*
  * Stop HC (not bus-specific)
  *
@@ -1009,7 +1044,7 @@ EXPORT_SYMBOL_GPL(xhci_suspend);
  */
 int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 {
-	u32			command, temp = 0, status;
+	u32			command, temp = 0;
 	struct usb_hcd		*hcd = xhci_to_hcd(xhci);
 	struct usb_hcd		*secondary_hcd;
 	int			retval = 0;
@@ -1043,8 +1078,13 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 		command = readl(&xhci->op_regs->command);
 		command |= CMD_CRS;
 		writel(command, &xhci->op_regs->command);
+		/*
+		 * Some controllers take up to 55+ ms to complete the controller
+		 * restore so setting the timeout to 100ms. Xhci specification
+		 * doesn't mention any timeout value.
+		 */
 		if (xhci_handshake(&xhci->op_regs->status,
-			      STS_RESTORE, 0, 10 * 1000)) {
+			      STS_RESTORE, 0, 100 * 1000)) {
 			xhci_warn(xhci, "WARN: xHC restore state timeout\n");
 			spin_unlock_irq(&xhci->lock);
 			return -ETIMEDOUT;
@@ -1134,8 +1174,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
  done:
 	if (retval == 0) {
 		/* Resume root hubs only when have pending events. */
-		status = readl(&xhci->op_regs->status);
-		if (status & STS_EINT) {
+		if (xhci_pending_portevent(xhci)) {
 			usb_hcd_resume_root_hub(xhci->shared_hcd);
 			usb_hcd_resume_root_hub(hcd);
 		}