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 9641e9c1dec5..ae10862fb041 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 59fb5c677dbe..f69720983fc7 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)