Merge tag 'for-usb-next-2013-01-03' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci into usb-next

Sarah writes:
	usb-next: Further warm reset improvements

	Hi Greg,

	Here's some patches for 3.9.  They further improve the warm reset
	error handling, but they're too big to go into stable.  There's also a
	patch to remove an unused variable in the xHCI driver.

	As I mentioned, you'll need to merge usb-linus into usb-next before
	applying these patches.

	Sarah Sharp

2 files changed, 107 insertions, 102 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 9641e9c1dec..ae10862fb04 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2535,77 +2535,9 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1,
 			return ret;
 
 		/* The port state is unknown until the reset completes. */
-		if ((portstatus & USB_PORT_STAT_RESET))
-			goto delay;
-
-		/*
-		 * Some buggy devices require a warm reset to be issued even
-		 * when the port appears not to be connected.
-		 */
-		if (!warm) {
-			/*
-			 * Some buggy devices can cause an NEC host controller
-			 * to transition to the "Error" state after a hot port
-			 * reset.  This will show up as the port state in
-			 * "Inactive", and the port may also report a
-			 * disconnect.  Forcing a warm port reset seems to make
-			 * the device work.
-			 *
-			 * See https://bugzilla.kernel.org/show_bug.cgi?id=41752
-			 */
-			if (hub_port_warm_reset_required(hub, portstatus)) {
-				int ret;
-
-				if ((portchange & USB_PORT_STAT_C_CONNECTION))
-					clear_port_feature(hub->hdev, port1,
-							USB_PORT_FEAT_C_CONNECTION);
-				if (portchange & USB_PORT_STAT_C_LINK_STATE)
-					clear_port_feature(hub->hdev, port1,
-							USB_PORT_FEAT_C_PORT_LINK_STATE);
-				if (portchange & USB_PORT_STAT_C_RESET)
-					clear_port_feature(hub->hdev, port1,
-							USB_PORT_FEAT_C_RESET);
-				dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
-						port1);
-				ret = hub_port_reset(hub, port1,
-						udev, HUB_BH_RESET_TIME,
-						true);
-				if ((portchange & USB_PORT_STAT_C_CONNECTION))
-					clear_port_feature(hub->hdev, port1,
-							USB_PORT_FEAT_C_CONNECTION);
-				return ret;
-			}
-			/* Device went away? */
-			if (!(portstatus & USB_PORT_STAT_CONNECTION))
-				return -ENOTCONN;
-
-			/* bomb out completely if the connection bounced */
-			if ((portchange & USB_PORT_STAT_C_CONNECTION))
-				return -ENOTCONN;
-
-			if ((portstatus & USB_PORT_STAT_ENABLE)) {
-				if (hub_is_wusb(hub))
-					udev->speed = USB_SPEED_WIRELESS;
-				else if (hub_is_superspeed(hub->hdev))
-					udev->speed = USB_SPEED_SUPER;
-				else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
-					udev->speed = USB_SPEED_HIGH;
-				else if (portstatus & USB_PORT_STAT_LOW_SPEED)
-					udev->speed = USB_SPEED_LOW;
-				else
-					udev->speed = USB_SPEED_FULL;
-				return 0;
-			}
-		} else {
-			if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
-					hub_port_warm_reset_required(hub,
-						portstatus))
-				return -ENOTCONN;
-
-			return 0;
-		}
+		if (!(portstatus & USB_PORT_STAT_RESET))
+			break;
 
-delay:
 		/* switch to the long delay after two short delay failures */
 		if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
 			delay = HUB_LONG_RESET_TIME;
@@ -2615,20 +2547,54 @@ delay:
 			port1, warm ? "warm " : "", delay);
 	}
 
-	return -EBUSY;
+	if ((portstatus & USB_PORT_STAT_RESET))
+		return -EBUSY;
+
+	if (hub_port_warm_reset_required(hub, portstatus))
+		return -ENOTCONN;
+
+	/* Device went away? */
+	if (!(portstatus & USB_PORT_STAT_CONNECTION))
+		return -ENOTCONN;
+
+	/* bomb out completely if the connection bounced.  A USB 3.0
+	 * connection may bounce if multiple warm resets were issued,
+	 * but the device may have successfully re-connected. Ignore it.
+	 */
+	if (!hub_is_superspeed(hub->hdev) &&
+			(portchange & USB_PORT_STAT_C_CONNECTION))
+		return -ENOTCONN;
+
+	if (!(portstatus & USB_PORT_STAT_ENABLE))
+		return -EBUSY;
+
+	if (!udev)
+		return 0;
+
+	if (hub_is_wusb(hub))
+		udev->speed = USB_SPEED_WIRELESS;
+	else if (hub_is_superspeed(hub->hdev))
+		udev->speed = USB_SPEED_SUPER;
+	else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
+		udev->speed = USB_SPEED_HIGH;
+	else if (portstatus & USB_PORT_STAT_LOW_SPEED)
+		udev->speed = USB_SPEED_LOW;
+	else
+		udev->speed = USB_SPEED_FULL;
+	return 0;
 }
 
 static void hub_port_finish_reset(struct usb_hub *hub, int port1,
-			struct usb_device *udev, int *status, bool warm)
+			struct usb_device *udev, int *status)
 {
 	switch (*status) {
 	case 0:
-		if (!warm) {
-			struct usb_hcd *hcd;
-			/* TRSTRCY = 10 ms; plus some extra */
-			msleep(10 + 40);
+		/* TRSTRCY = 10 ms; plus some extra */
+		msleep(10 + 40);
+		if (udev) {
+			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
 			update_devnum(udev, 0);
-			hcd = bus_to_hcd(udev->bus);
 			/* The xHC may think the device is already reset,
 			 * so ignore the status.
 			 */
@@ -2640,14 +2606,15 @@ static void hub_port_finish_reset(struct usb_hub *hub, int port1,
 	case -ENODEV:
 		clear_port_feature(hub->hdev,
 				port1, USB_PORT_FEAT_C_RESET);
-		/* FIXME need disconnect() for NOTATTACHED device */
 		if (hub_is_superspeed(hub->hdev)) {
 			clear_port_feature(hub->hdev, port1,
 					USB_PORT_FEAT_C_BH_PORT_RESET);
 			clear_port_feature(hub->hdev, port1,
 					USB_PORT_FEAT_C_PORT_LINK_STATE);
+			clear_port_feature(hub->hdev, port1,
+					USB_PORT_FEAT_C_CONNECTION);
 		}
-		if (!warm)
+		if (udev)
 			usb_set_device_state(udev, *status
 					? USB_STATE_NOTATTACHED
 					: USB_STATE_DEFAULT);
@@ -2660,18 +2627,30 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 			struct usb_device *udev, unsigned int delay, bool warm)
 {
 	int i, status;
+	u16 portchange, portstatus;
 
-	if (!warm) {
-		/* Block EHCI CF initialization during the port reset.
-		 * Some companion controllers don't like it when they mix.
-		 */
-		down_read(&ehci_cf_port_reset_rwsem);
-	} else {
-		if (!hub_is_superspeed(hub->hdev)) {
+	if (!hub_is_superspeed(hub->hdev)) {
+		if (warm) {
 			dev_err(hub->intfdev, "only USB3 hub support "
 						"warm reset\n");
 			return -EINVAL;
 		}
+		/* Block EHCI CF initialization during the port reset.
+		 * Some companion controllers don't like it when they mix.
+		 */
+		down_read(&ehci_cf_port_reset_rwsem);
+	} else if (!warm) {
+		/*
+		 * If the caller hasn't explicitly requested a warm reset,
+		 * double check and see if one is needed.
+		 */
+		status = hub_port_status(hub, port1,
+					&portstatus, &portchange);
+		if (status < 0)
+			goto done;
+
+		if (hub_port_warm_reset_required(hub, portstatus))
+			warm = true;
 	}
 
 	/* Reset the port */
@@ -2692,10 +2671,33 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 						status);
 		}
 
-		/* return on disconnect or reset */
+		/* Check for disconnect or reset */
 		if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
-			hub_port_finish_reset(hub, port1, udev, &status, warm);
-			goto done;
+			hub_port_finish_reset(hub, port1, udev, &status);
+
+			if (!hub_is_superspeed(hub->hdev))
+				goto done;
+
+			/*
+			 * If a USB 3.0 device migrates from reset to an error
+			 * state, re-issue the warm reset.
+			 */
+			if (hub_port_status(hub, port1,
+					&portstatus, &portchange) < 0)
+				goto done;
+
+			if (!hub_port_warm_reset_required(hub, portstatus))
+				goto done;
+
+			/*
+			 * If the port is in SS.Inactive or Compliance Mode, the
+			 * hot or warm reset failed.  Try another warm reset.
+			 */
+			if (!warm) {
+				dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
+						port1);
+				warm = true;
+			}
 		}
 
 		dev_dbg (hub->intfdev,
@@ -2709,7 +2711,7 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
 		port1);
 
 done:
-	if (!warm)
+	if (!hub_is_superspeed(hub->hdev))
 		up_read(&ehci_cf_port_reset_rwsem);
 
 	return status;
@@ -2945,9 +2947,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 
 	/* see 7.1.7.6 */
 	if (hub_is_superspeed(hub->hdev))
-		status = set_port_feature(hub->hdev,
-				port1 | (USB_SS_PORT_LS_U3 << 3),
-				USB_PORT_FEAT_LINK_STATE);
+		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
 	else
 		status = set_port_feature(hub->hdev, port1,
 						USB_PORT_FEAT_SUSPEND);
@@ -3117,9 +3117,7 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 
 	/* see 7.1.7.7; affects power usage, but not budgeting */
 	if (hub_is_superspeed(hub->hdev))
-		status = set_port_feature(hub->hdev,
-				port1 | (USB_SS_PORT_LS_U0 << 3),
-				USB_PORT_FEAT_LINK_STATE);
+		status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
 	else
 		status = clear_port_feature(hub->hdev,
 				port1, USB_PORT_FEAT_SUSPEND);
@@ -4700,12 +4698,21 @@ static void hub_events(void)
 			 */
 			if (hub_port_warm_reset_required(hub, portstatus)) {
 				int status;
+				struct usb_device *udev =
+					hub->ports[i - 1]->child;
 
 				dev_dbg(hub_dev, "warm reset port %d\n", i);
-				status = hub_port_reset(hub, i, NULL,
-						HUB_BH_RESET_TIME, true);
-				if (status < 0)
-					hub_port_disable(hub, i, 1);
+				if (!udev) {
+					status = hub_port_reset(hub, i,
+							NULL, HUB_BH_RESET_TIME,
+							true);
+					if (status < 0)
+						hub_port_disable(hub, i, 1);
+				} else {
+					usb_lock_device(udev);
+					status = usb_reset_device(udev);
+					usb_unlock_device(udev);
+				}
 				connect_change = 0;
 			}
 
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 59fb5c677db..f69720983fc 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2706,13 +2706,11 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	u32 status;
-	union xhci_trb *trb;
 	u64 temp_64;
 	union xhci_trb *event_ring_deq;
 	dma_addr_t deq;
 
 	spin_lock(&xhci->lock);
-	trb = xhci->event_ring->dequeue;
 	/* Check if the xHC generated the interrupt, or the irq is shared */
 	status = xhci_readl(xhci, &xhci->op_regs->status);
 	if (status == 0xffffffff)