6 files changed, 92 insertions, 33 deletions

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index dde4c83516a1..e6b682c6c236 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3426,6 +3426,9 @@ static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
         unsigned long long u2_pel;
         int ret;
 
+        if (udev->state != USB_STATE_CONFIGURED)
+                return 0;
+
         /* Convert SEL and PEL stored in ns to us */
         u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
         u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index fae697ed0b70..773a6b28c4f1 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -287,7 +287,7 @@ static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
                 if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue)
                         xhci_queue_stop_endpoint(xhci, slot_id, i, suspend);
         }
-        cmd->command_trb = xhci->cmd_ring->enqueue;
+        cmd->command_trb = xhci_find_next_enqueue(xhci->cmd_ring);
         list_add_tail(&cmd->cmd_list, &virt_dev->cmd_list);
         xhci_queue_stop_endpoint(xhci, slot_id, 0, suspend);
         xhci_ring_cmd_db(xhci);
@@ -552,11 +552,15 @@ void xhci_del_comp_mod_timer(struct xhci_hcd *xhci, u32 status, u16 wIndex)
  *  - Mark a port as being done with device resume,
  *    and ring the endpoint doorbells.
  *  - Stop the Synopsys redriver Compliance Mode polling.
+ *  - Drop and reacquire the xHCI lock, in order to wait for port resume.
  */
 static u32 xhci_get_port_status(struct usb_hcd *hcd,
                 struct xhci_bus_state *bus_state,
                 __le32 __iomem **port_array,
-                u16 wIndex, u32 raw_port_status)
+                u16 wIndex, u32 raw_port_status,
+                unsigned long flags)
+        __releases(&xhci->lock)
+        __acquires(&xhci->lock)
 {
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         u32 status = 0;
@@ -591,21 +595,42 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
                         return 0xffffffff;
                 if (time_after_eq(jiffies,
                                         bus_state->resume_done[wIndex])) {
+                        int time_left;
+
                         xhci_dbg(xhci, "Resume USB2 port %d\n",
                                         wIndex + 1);
                         bus_state->resume_done[wIndex] = 0;
                         clear_bit(wIndex, &bus_state->resuming_ports);
+
+                        set_bit(wIndex, &bus_state->rexit_ports);
                         xhci_set_link_state(xhci, port_array, wIndex,
                                         XDEV_U0);
-                        xhci_dbg(xhci, "set port %d resume\n",
-                                        wIndex + 1);
-                        slot_id = xhci_find_slot_id_by_port(hcd, xhci,
-                                        wIndex + 1);
-                        if (!slot_id) {
-                                xhci_dbg(xhci, "slot_id is zero\n");
-                                return 0xffffffff;
+
+                        spin_unlock_irqrestore(&xhci->lock, flags);
+                        time_left = wait_for_completion_timeout(
+                                        &bus_state->rexit_done[wIndex],
+                                        msecs_to_jiffies(
+                                                XHCI_MAX_REXIT_TIMEOUT));
+                        spin_lock_irqsave(&xhci->lock, flags);
+
+                        if (time_left) {
+                                slot_id = xhci_find_slot_id_by_port(hcd,
+                                                xhci, wIndex + 1);
+                                if (!slot_id) {
+                                        xhci_dbg(xhci, "slot_id is zero\n");
+                                        return 0xffffffff;
+                                }
+                                xhci_ring_device(xhci, slot_id);
+                        } else {
+                                int port_status = xhci_readl(xhci,
+                                                port_array[wIndex]);
+                                xhci_warn(xhci, "Port resume took longer than %i msec, port status = 0x%x\n",
+                                                XHCI_MAX_REXIT_TIMEOUT,
+                                                port_status);
+                                status |= USB_PORT_STAT_SUSPEND;
+                                clear_bit(wIndex, &bus_state->rexit_ports);
                         }
-                        xhci_ring_device(xhci, slot_id);
+
                         bus_state->port_c_suspend |= 1 << wIndex;
                         bus_state->suspended_ports &= ~(1 << wIndex);
                 } else {
@@ -728,7 +753,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                         break;
                 }
                 status = xhci_get_port_status(hcd, bus_state, port_array,
-                                wIndex, temp);
+                                wIndex, temp, flags);
                 if (status == 0xffffffff)
                         goto error;
 
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 53b972c2a09f..83bcd13622c3 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2428,6 +2428,8 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
         for (i = 0; i < USB_MAXCHILDREN; ++i) {
                 xhci->bus_state[0].resume_done[i] = 0;
                 xhci->bus_state[1].resume_done[i] = 0;
+                /* Only the USB 2.0 completions will ever be used. */
+                init_completion(&xhci->bus_state[1].rexit_done[i]);
         }
 
         if (scratchpad_alloc(xhci, flags))
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 411da1fc7ae8..6bfbd80ec2b9 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -123,6 +123,16 @@ static int enqueue_is_link_trb(struct xhci_ring *ring)
         return TRB_TYPE_LINK_LE32(link->control);
 }
 
+union xhci_trb *xhci_find_next_enqueue(struct xhci_ring *ring)
+{
+        /* Enqueue pointer can be left pointing to the link TRB,
+         * we must handle that
+         */
+        if (TRB_TYPE_LINK_LE32(ring->enqueue->link.control))
+                return ring->enq_seg->next->trbs;
+        return ring->enqueue;
+}
+
 /* Updates trb to point to the next TRB in the ring, and updates seg if the next
  * TRB is in a new segment.  This does not skip over link TRBs, and it does not
  * effect the ring dequeue or enqueue pointers.
@@ -859,8 +869,12 @@ remove_finished_td:
                 /* Otherwise ring the doorbell(s) to restart queued transfers */
                 ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
         }
-        ep->stopped_td = NULL;
-        ep->stopped_trb = NULL;
+
+        /* Clear stopped_td and stopped_trb if endpoint is not halted */
+        if (!(ep->ep_state & EP_HALTED)) {
+                ep->stopped_td = NULL;
+                ep->stopped_trb = NULL;
+        }
 
         /*
          * Drop the lock and complete the URBs in the cancelled TD list.
@@ -1414,6 +1428,12 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
                         inc_deq(xhci, xhci->cmd_ring);
                         return;
                 }
+                /* There is no command to handle if we get a stop event when the
+                 * command ring is empty, event->cmd_trb points to the next
+                 * unset command
+                 */
+                if (xhci->cmd_ring->dequeue == xhci->cmd_ring->enqueue)
+                        return;
         }
 
         switch (le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3])
@@ -1743,6 +1763,19 @@ static void handle_port_status(struct xhci_hcd *xhci,
                 }
         }
 
+        /*
+         * Check to see if xhci-hub.c is waiting on RExit to U0 transition (or
+         * RExit to a disconnect state).  If so, let the the driver know it's
+         * out of the RExit state.
+         */
+        if (!DEV_SUPERSPEED(temp) &&
+                        test_and_clear_bit(faked_port_index,
+                                &bus_state->rexit_ports)) {
+                complete(&bus_state->rexit_done[faked_port_index]);
+                bogus_port_status = true;
+                goto cleanup;
+        }
+
         if (hcd->speed != HCD_USB3)
                 xhci_test_and_clear_bit(xhci, port_array, faked_port_index,
                                         PORT_PLC);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 49b6edb84a79..1e36dbb48366 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2598,15 +2598,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
         if (command) {
                 cmd_completion = command->completion;
                 cmd_status = &command->status;
-                command->command_trb = xhci->cmd_ring->enqueue;
-
-                /* Enqueue pointer can be left pointing to the link TRB,
-                 * we must handle that
-                 */
-                if (TRB_TYPE_LINK_LE32(command->command_trb->link.control))
-                        command->command_trb =
-                                xhci->cmd_ring->enq_seg->next->trbs;
-
+                command->command_trb = xhci_find_next_enqueue(xhci->cmd_ring);
                 list_add_tail(&command->cmd_list, &virt_dev->cmd_list);
         } else {
                 cmd_completion = &virt_dev->cmd_completion;
@@ -2614,7 +2606,7 @@ static int xhci_configure_endpoint(struct xhci_hcd *xhci,
         }
         init_completion(cmd_completion);
 
-        cmd_trb = xhci->cmd_ring->dequeue;
+        cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
         if (!ctx_change)
                 ret = xhci_queue_configure_endpoint(xhci, in_ctx->dma,
                                 udev->slot_id, must_succeed);
@@ -3439,14 +3431,7 @@ int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
 
         /* Attempt to submit the Reset Device command to the command ring */
         spin_lock_irqsave(&xhci->lock, flags);
-        reset_device_cmd->command_trb = xhci->cmd_ring->enqueue;
-
-        /* Enqueue pointer can be left pointing to the link TRB,
-         * we must handle that
-         */
-        if (TRB_TYPE_LINK_LE32(reset_device_cmd->command_trb->link.control))
-                reset_device_cmd->command_trb =
-                        xhci->cmd_ring->enq_seg->next->trbs;
+        reset_device_cmd->command_trb = xhci_find_next_enqueue(xhci->cmd_ring);
 
         list_add_tail(&reset_device_cmd->cmd_list, &virt_dev->cmd_list);
         ret = xhci_queue_reset_device(xhci, slot_id);
@@ -3650,7 +3635,7 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
         union xhci_trb *cmd_trb;
 
         spin_lock_irqsave(&xhci->lock, flags);
-        cmd_trb = xhci->cmd_ring->dequeue;
+        cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
         ret = xhci_queue_slot_control(xhci, TRB_ENABLE_SLOT, 0);
         if (ret) {
                 spin_unlock_irqrestore(&xhci->lock, flags);
@@ -3785,7 +3770,7 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
                                 slot_ctx->dev_info >> 27);
 
         spin_lock_irqsave(&xhci->lock, flags);
-        cmd_trb = xhci->cmd_ring->dequeue;
+        cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
         ret = xhci_queue_address_device(xhci, virt_dev->in_ctx->dma,
                                         udev->slot_id);
         if (ret) {
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 46aa14894148..289fbfbae746 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1412,8 +1412,18 @@ struct xhci_bus_state {
         unsigned long           resume_done[USB_MAXCHILDREN];
         /* which ports have started to resume */
         unsigned long           resuming_ports;
+        /* Which ports are waiting on RExit to U0 transition. */
+        unsigned long           rexit_ports;
+        struct completion       rexit_done[USB_MAXCHILDREN];
 };
 
+
+/*
+ * It can take up to 20 ms to transition from RExit to U0 on the
+ * Intel Lynx Point LP xHCI host.
+ */
+#define XHCI_MAX_REXIT_TIMEOUT  (20 * 1000)
+
 static inline unsigned int hcd_index(struct usb_hcd *hcd)
 {
         if (hcd->speed == HCD_USB3)
@@ -1840,6 +1850,7 @@ int xhci_cancel_cmd(struct xhci_hcd *xhci, struct xhci_command *command,
                 union xhci_trb *cmd_trb);
 void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, unsigned int slot_id,
                 unsigned int ep_index, unsigned int stream_id);
+union xhci_trb *xhci_find_next_enqueue(struct xhci_ring *ring);
 
 /* xHCI roothub code */
 void xhci_set_link_state(struct xhci_hcd *xhci, __le32 __iomem **port_array,