rt2x00: fix hang when unplugging USB device in use

commit d7bb5f845f437662296adbfeaab8fbfce1c32289 upstream.

When an rt2x00 USB device is unplugged while in use, it reliably
hangs the whole system.  After some time the watchdog prints:

BUG: soft lockup - CPU#0 stuck for 64s! [kworker/u:0:5]
...
[<c01a88d8>] (usb_submit_urb+0x0/0x2ac) from [<bf0e752c>] (rt2x00usb_kick_rx_entry+0xb4/0xe8 [rt2x00usb])
[<bf0e7478>] (rt2x00usb_kick_rx_entry+0x0/0xe8 [rt2x00usb]) from [<bf0e7588>] (rt2x00usb_clear_entry+x28/0x2c [rt2x00usb])
[<bf0e7560>] (rt2x00usb_clear_entry+0x0/0x2c [rt2x00usb]) from [<bf0d5bc4>] (rt2x00lib_rxdone+0x2e0/0x2f8 [rt2x00lib])
[<bf0d58e4>] (rt2x00lib_rxdone+0x0/0x2f8 [rt2x00lib]) from [<bf0e7e00>] (rt2x00usb_work_rxdone+0x54/0x74 [rt2x00usb])
[<bf0e7dac>] (rt2x00usb_work_rxdone+0x0/0x74 [rt2x00usb]) from [<c00542b4>] (process_one_work+0x20c/0x35c)

Clear the DEVICE_STATE_PRESENT flag when usb_submit_urb()
returns -ENODEV to fix this.

Signed-off-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index a1084914706219db7208fb61fe7137a1dcbefcd9..051758fbfc3030169153875f2b8a3aa0cdefb0d6 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -235,6 +235,7 @@ static void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
        struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
        struct queue_entry_priv_usb *entry_priv = entry->priv_data;
        u32 length;
+       int status;
 
        if (!test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
                return;
@@ -251,7 +252,10 @@ static void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
                          entry->skb->data, length,
                          rt2x00usb_interrupt_txdone, entry);
 
-       if (usb_submit_urb(entry_priv->urb, GFP_ATOMIC)) {
+       status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
+       if (status) {
+               if (status == -ENODEV)
+                       clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
                set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
                rt2x00lib_dmadone(entry);
        }
@@ -450,6 +454,7 @@ void rt2x00usb_clear_entry(struct queue_entry *entry)
            to_usb_device_intf(entry->queue->rt2x00dev->dev);
        struct queue_entry_priv_usb *entry_priv = entry->priv_data;
        int pipe;
+       int status;
 
        entry->flags = 0;
 
@@ -460,7 +465,12 @@ void rt2x00usb_clear_entry(struct queue_entry *entry)
                                rt2x00usb_interrupt_rxdone, entry);
 
                set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
-               if (usb_submit_urb(entry_priv->urb, GFP_ATOMIC)) {
+
+               status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
+               if (status) {
+                       if (status == -ENODEV)
+                               clear_bit(DEVICE_STATE_PRESENT,
+                                         &entry->queue->rt2x00dev->flags);
                        set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
                        rt2x00lib_dmadone(entry);
                }