xhci: Use delayed_work instead of timer for command timeout

This is preparation to fix abort operation race (See "xhci: Fix race
related to abort operation"). To make timeout sleepable, use
delayed_work instead of timer.

[change a newly added pending timer fix to pending work -Mathias]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-mem.c

@@ -1829,7 +1829,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	int size;
 	int i, j, num_ports;
 
-	del_timer_sync(&xhci->cmd_timer);
+	cancel_delayed_work_sync(&xhci->cmd_timer);
 
 	/* Free the Event Ring Segment Table and the actual Event Ring */
 	size = sizeof(struct xhci_erst_entry)*(xhci->erst.num_entries);
@@ -2376,9 +2376,8 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 
 	INIT_LIST_HEAD(&xhci->cmd_list);
 
-	/* init command timeout timer */
-	setup_timer(&xhci->cmd_timer, xhci_handle_command_timeout,
-		    (unsigned long)xhci);
+	/* init command timeout work */
+	INIT_DELAYED_WORK(&xhci->cmd_timer, xhci_handle_command_timeout);
 
 	page_size = readl(&xhci->op_regs->page_size);
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,

drivers/usb/host/xhci-ring.c

@@ -279,6 +279,11 @@ void xhci_ring_cmd_db(struct xhci_hcd *xhci)
 	readl(&xhci->dba->doorbell[0]);
 }
 
+static bool xhci_mod_cmd_timer(struct xhci_hcd *xhci, unsigned long delay)
+{
+	return mod_delayed_work(system_wq, &xhci->cmd_timer, delay);
+}
+
 static int xhci_abort_cmd_ring(struct xhci_hcd *xhci)
 {
 	u64 temp_64;
@@ -295,7 +300,7 @@ static int xhci_abort_cmd_ring(struct xhci_hcd *xhci)
 	 * 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_mod_cmd_timer(xhci, 2 * XHCI_CMD_DEFAULT_TIMEOUT);
 	xhci_write_64(xhci, temp_64 | CMD_RING_ABORT,
 			&xhci->op_regs->cmd_ring);
 
@@ -320,7 +325,7 @@ static int xhci_abort_cmd_ring(struct xhci_hcd *xhci)
 
 		xhci_err(xhci, "Stopped the command ring failed, "
 				"maybe the host is dead\n");
-		del_timer(&xhci->cmd_timer);
+		cancel_delayed_work(&xhci->cmd_timer);
 		xhci->xhc_state |= XHCI_STATE_DYING;
 		xhci_halt(xhci);
 		return -ESHUTDOWN;
@@ -1251,21 +1256,22 @@ static void xhci_handle_stopped_cmd_ring(struct xhci_hcd *xhci,
 	if ((xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue) &&
 	    !(xhci->xhc_state & XHCI_STATE_DYING)) {
 		xhci->current_cmd = cur_cmd;
-		mod_timer(&xhci->cmd_timer, jiffies + XHCI_CMD_DEFAULT_TIMEOUT);
+		xhci_mod_cmd_timer(xhci, XHCI_CMD_DEFAULT_TIMEOUT);
 		xhci_ring_cmd_db(xhci);
 	}
 	return;
 }
 
 
-void xhci_handle_command_timeout(unsigned long data)
+void xhci_handle_command_timeout(struct work_struct *work)
 {
 	struct xhci_hcd *xhci;
 	int ret;
 	unsigned long flags;
 	u64 hw_ring_state;
 	bool second_timeout = false;
-	xhci = (struct xhci_hcd *) data;
+
+	xhci = container_of(to_delayed_work(work), struct xhci_hcd, cmd_timer);
 
 	spin_lock_irqsave(&xhci->lock, flags);
 
@@ -1273,7 +1279,7 @@ void xhci_handle_command_timeout(unsigned long data)
 	 * If timeout work is pending, or current_cmd is NULL, it means we
 	 * raced with command completion. Command is handled so just return.
 	 */
-	if (!xhci->current_cmd || timer_pending(&xhci->cmd_timer)) {
+	if (!xhci->current_cmd || delayed_work_pending(&xhci->cmd_timer)) {
 		spin_unlock_irqrestore(&xhci->lock, flags);
 		return;
 	}
@@ -1346,7 +1352,7 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
 
 	cmd = list_entry(xhci->cmd_list.next, struct xhci_command, cmd_list);
 
-	del_timer(&xhci->cmd_timer);
+	cancel_delayed_work(&xhci->cmd_timer);
 
 	trace_xhci_cmd_completion(cmd_trb, (struct xhci_generic_trb *) event);
 
@@ -1437,7 +1443,7 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
 	if (cmd->cmd_list.next != &xhci->cmd_list) {
 		xhci->current_cmd = list_entry(cmd->cmd_list.next,
 					       struct xhci_command, cmd_list);
-		mod_timer(&xhci->cmd_timer, jiffies + XHCI_CMD_DEFAULT_TIMEOUT);
+		xhci_mod_cmd_timer(xhci, XHCI_CMD_DEFAULT_TIMEOUT);
 	} else if (xhci->current_cmd == cmd) {
 		xhci->current_cmd = NULL;
 	}
@@ -3808,9 +3814,9 @@ static int queue_command(struct xhci_hcd *xhci, struct xhci_command *cmd,
 
 	/* if there are no other commands queued we start the timeout timer */
 	if (xhci->cmd_list.next == &cmd->cmd_list &&
-	    !timer_pending(&xhci->cmd_timer)) {
+	    !delayed_work_pending(&xhci->cmd_timer)) {
 		xhci->current_cmd = cmd;
-		mod_timer(&xhci->cmd_timer, jiffies + XHCI_CMD_DEFAULT_TIMEOUT);
+		xhci_mod_cmd_timer(xhci, XHCI_CMD_DEFAULT_TIMEOUT);
 	}
 
 	queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,

drivers/usb/host/xhci.h

@@ -1568,7 +1568,7 @@ struct xhci_hcd {
 #define CMD_RING_STATE_STOPPED         (1 << 2)
 	struct list_head        cmd_list;
 	unsigned int		cmd_ring_reserved_trbs;
-	struct timer_list	cmd_timer;
+	struct delayed_work	cmd_timer;
 	struct xhci_command	*current_cmd;
 	struct xhci_ring	*event_ring;
 	struct xhci_erst	erst;
@@ -1934,7 +1934,7 @@ void xhci_queue_config_ep_quirk(struct xhci_hcd *xhci,
 		unsigned int slot_id, unsigned int ep_index,
 		struct xhci_dequeue_state *deq_state);
 void xhci_stop_endpoint_command_watchdog(unsigned long arg);
-void xhci_handle_command_timeout(unsigned long data);
+void xhci_handle_command_timeout(struct work_struct *work);
 
 void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, unsigned int slot_id,
 		unsigned int ep_index, unsigned int stream_id);