wl12xx: fix potential race condition with TX queue watermark

Browse source

Check the conditions for the high/low TX queue watermarks when the
spin-lock is taken. This prevents race conditions as tx_queue_count and
the flag checked are only modified when the spin-lock is taken.

The following race was in mind:
- Queues are almost full and wl1271_op_tx() will stop the queues, but it
  doesn't get the spin-lock yet.
- (on another CPU) tx_work_locked() dequeues 15 skbs from this queue and
  tx_queue_count is updated to reflect this
- wl1271_op_tx() does not check tx_queue_count after taking the
  spin-lock and incorrectly stops the queue.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

...

This commit is contained in:

Arik Nemtsov 2011-02-23 00:22:24 +02:00 • committed by Luciano Coelho

parent 6dc9fb3c78

commit f4d08ddd3e

1 changed files with 11 additions and 13 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

24

drivers/net/wireless/wl12xx/main.c

View file