1 files changed, 77 insertions, 5 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index cc1993c5556e..2dd322e92951 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -619,8 +619,30 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 		if ((raw_port_status & PORT_RESET) ||
 				!(raw_port_status & PORT_PE))
 			return 0xffffffff;
-		if (time_after_eq(jiffies,
-					bus_state->resume_done[wIndex])) {
+		/* did port event handler already start resume timing? */
+		if (!bus_state->resume_done[wIndex]) {
+			/* If not, maybe we are in a host initated resume? */
+			if (test_bit(wIndex, &bus_state->resuming_ports)) {
+				/* Host initated resume doesn't time the resume
+				 * signalling using resume_done[].
+				 * It manually sets RESUME state, sleeps 20ms
+				 * and sets U0 state. This should probably be
+				 * changed, but not right now.
+				 */
+			} else {
+				/* port resume was discovered now and here,
+				 * start resume timing
+				 */
+				unsigned long timeout = jiffies +
+					msecs_to_jiffies(USB_RESUME_TIMEOUT);
+
+				set_bit(wIndex, &bus_state->resuming_ports);
+				bus_state->resume_done[wIndex] = timeout;
+				mod_timer(&hcd->rh_timer, timeout);
+			}
+		/* Has resume been signalled for USB_RESUME_TIME yet? */
+		} else if (time_after_eq(jiffies,
+					 bus_state->resume_done[wIndex])) {
 			int time_left;
 
 			xhci_dbg(xhci, "Resume USB2 port %d\n",
@@ -661,13 +683,24 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
 		} else {
 			/*
 			 * The resume has been signaling for less than
-			 * 20ms. Report the port status as SUSPEND,
-			 * let the usbcore check port status again
-			 * and clear resume signaling later.
+			 * USB_RESUME_TIME. Report the port status as SUSPEND,
+			 * let the usbcore check port status again and clear
+			 * resume signaling later.
 			 */
 			status |= USB_PORT_STAT_SUSPEND;
 		}
 	}
+	/*
+	 * Clear stale usb2 resume signalling variables in case port changed
+	 * state during resume signalling. For example on error
+	 */
+	if ((bus_state->resume_done[wIndex] ||
+	     test_bit(wIndex, &bus_state->resuming_ports)) &&
+	    (raw_port_status & PORT_PLS_MASK) != XDEV_U3 &&
+	    (raw_port_status & PORT_PLS_MASK) != XDEV_RESUME) {
+		bus_state->resume_done[wIndex] = 0;
+		clear_bit(wIndex, &bus_state->resuming_ports);
+	}
 	if ((raw_port_status & PORT_PLS_MASK) == XDEV_U0
 			&& (raw_port_status & PORT_POWER)
 			&& (bus_state->suspended_ports & (1 << wIndex))) {
@@ -998,6 +1031,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				if ((temp & PORT_PE) == 0)
 					goto error;
 
+				set_bit(wIndex, &bus_state->resuming_ports);
 				xhci_set_link_state(xhci, port_array, wIndex,
 							XDEV_RESUME);
 				spin_unlock_irqrestore(&xhci->lock, flags);
@@ -1005,6 +1039,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 				spin_lock_irqsave(&xhci->lock, flags);
 				xhci_set_link_state(xhci, port_array, wIndex,
 							XDEV_U0);
+				clear_bit(wIndex, &bus_state->resuming_ports);
 			}
 			bus_state->port_c_suspend |= 1 << wIndex;
 
@@ -1189,6 +1224,35 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 	return 0;
 }
 
+/*
+ * Workaround for missing Cold Attach Status (CAS) if device re-plugged in S3.
+ * warm reset a USB3 device stuck in polling or compliance mode after resume.
+ * See Intel 100/c230 series PCH specification update Doc #332692-006 Errata #8
+ */
+static bool xhci_port_missing_cas_quirk(int port_index,
+					     __le32 __iomem **port_array)
+{
+	u32 portsc;
+
+	portsc = readl(port_array[port_index]);
+
+	/* if any of these are set we are not stuck */
+	if (portsc & (PORT_CONNECT | PORT_CAS))
+		return false;
+
+	if (((portsc & PORT_PLS_MASK) != XDEV_POLLING) &&
+	    ((portsc & PORT_PLS_MASK) != XDEV_COMP_MODE))
+		return false;
+
+	/* clear wakeup/change bits, and do a warm port reset */
+	portsc &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
+	portsc |= PORT_WR;
+	writel(portsc, port_array[port_index]);
+	/* flush write */
+	readl(port_array[port_index]);
+	return true;
+}
+
 int xhci_bus_resume(struct usb_hcd *hcd)
 {
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
@@ -1223,6 +1287,14 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 		int slot_id;
 
 		temp = readl(port_array[port_index]);
+
+		/* warm reset CAS limited ports stuck in polling/compliance */
+		if ((xhci->quirks & XHCI_MISSING_CAS) &&
+		    (hcd->speed >= HCD_USB3) &&
+		    xhci_port_missing_cas_quirk(port_index, port_array)) {
+			xhci_dbg(xhci, "reset stuck port %d\n", port_index);
+			continue;
+		}
 		if (DEV_SUPERSPEED(temp))
 			temp &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
 		else