zd1211rw: use urb anchors for tx and fix tx-queue disabling

When stress testing AP-mode I hit OOPS when unpluging or rmmodding
driver.

It appears that when tx-queue is disabled, tx-urbs might be left pending.
These can cause ehci to call non-existing tx_urb_complete() (after rmmod)
or uninitialized/reseted private structure (after disconnect()). Add skb
queue for submitted packets and unlink pending urbs on zd_usb_disable_tx().

Part of the problem seems to be usb->free_urb_list that isn't always
working as it should, causing machine freeze when trying to free the list
in zd_usb_disable_tx(). Caching free urbs isn't what other drivers seem
to be doing (usbnet for example) so strip free_usb_list.

Patch makes tx-urb handling saner with use of urb anchors.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_usb.h b/drivers/net/wireless/zd1211rw/zd_usb.h
index 1b1655cb7cb..233ce825b71 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.h
+++ b/drivers/net/wireless/zd1211rw/zd_usb.h
@@ -184,18 +184,18 @@ struct zd_usb_rx {
 
 /**
  * struct zd_usb_tx - structure used for transmitting frames
+ * @enabled: atomic enabled flag, indicates whether tx is enabled
  * @lock: lock for transmission
- * @free_urb_list: list of free URBs, contains all the URBs, which can be used
+ * @submitted: anchor for URBs sent to device
  * @submitted_urbs: atomic integer that counts the URBs having sent to the
  *      device, which haven't been completed
- * @enabled: enabled flag, indicates whether tx is enabled
  * @stopped: indicates whether higher level tx queues are stopped
  */
 struct zd_usb_tx {
+        atomic_t enabled;
         spinlock_t lock;
-        struct list_head free_urb_list;
+        struct usb_anchor submitted;
         int submitted_urbs;
-        int enabled;
         int stopped;
 };