Patch "xhci: Fix handling timeouted commands on hosts in weird states." has been added to the 4.6-stable tree

@@ -290,6 +290,14 @@ static int xhci_abort_cmd_ring(struct xh
 
 	temp_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring);
 	xhci->cmd_ring_state = CMD_RING_STATE_ABORTED;
+
+	/*
+	 * Writing the CMD_RING_ABORT bit should cause a cmd completion event,
+	 * however on some host hw the CMD_RING_RUNNING bit is correctly cleared
+	 * but the completion event in never sent. Use the cmd timeout timer to
+	 * handle those cases. Use twice the time to cover the bit polling retry
+	 */
+	mod_timer(&xhci->cmd_timer, jiffies + (2 * XHCI_CMD_DEFAULT_TIMEOUT));
 	xhci_write_64(xhci, temp_64 | CMD_RING_ABORT,
 			&xhci->op_regs->cmd_ring);
 

@@ -314,6 +322,7 @@ static int xhci_abort_cmd_ring(struct xh
 
 		xhci_err(xhci, "Stopped the command ring failed, "
 				"maybe the host is dead\n");
+		del_timer(&xhci->cmd_timer);
 		xhci->xhc_state |= XHCI_STATE_DYING;
 		xhci_quiesce(xhci);
 		xhci_halt(xhci);

@@ -1253,22 +1262,21 @@ void xhci_handle_command_timeout(unsigne
 	int ret;
 	unsigned long flags;
 	u64 hw_ring_state;
-	struct xhci_command *cur_cmd = NULL;
+	bool second_timeout = false;
 	xhci = (struct xhci_hcd *) data;
 
 	/* mark this command to be cancelled */
 	spin_lock_irqsave(&xhci->lock, flags);
 	if (xhci->current_cmd) {
-		cur_cmd = xhci->current_cmd;
-		cur_cmd->status = COMP_CMD_ABORT;
+		if (xhci->current_cmd->status == COMP_CMD_ABORT)
+			second_timeout = true;
+		xhci->current_cmd->status = COMP_CMD_ABORT;
 	}
 
-
 	/* Make sure command ring is running before aborting it */
 	hw_ring_state = xhci_read_64(xhci, &xhci->op_regs->cmd_ring);
 	if ((xhci->cmd_ring_state & CMD_RING_STATE_RUNNING) &&
 	    (hw_ring_state & CMD_RING_RUNNING))  {
-
 		spin_unlock_irqrestore(&xhci->lock, flags);
 		xhci_dbg(xhci, "Command timeout\n");
 		ret = xhci_abort_cmd_ring(xhci);

@@ -1280,6 +1288,15 @@ void xhci_handle_command_timeout(unsigne
 		}
 		return;
 	}
+
+	/* command ring failed to restart, or host removed. Bail out */
+	if (second_timeout || xhci->xhc_state & XHCI_STATE_REMOVING) {
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		xhci_dbg(xhci, "command timed out twice, ring start fail?\n");
+		xhci_cleanup_command_queue(xhci);
+		return;
+	}
+
 	/* command timeout on stopped ring, ring can't be aborted */
 	xhci_dbg(xhci, "Command timeout on stopped ring\n");
 	xhci_handle_stopped_cmd_ring(xhci, xhci->current_cmd);