wl1251: Fix queue stopping/waking for TX path
This patch was adapted from 06f7bc7db79fabe6b2ec16eff0f59e4acc21eb72
(from linus's linux-2.6 tree of kernel.org)
here's the original message:
The queue stopping/waking functionality was broken in a way that could
cause huge latencies in TX transfers and even cause the TX to stall in the
right circumstances. Correct these problems.
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Acked-by: Kalle Valo <kvalo@adurom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/wl1251_main.c b/drivers/net/wireless/wl12xx/wl1251_main.c
index f9d9ad6..faf221c 100644
--- a/drivers/net/wireless/wl12xx/wl1251_main.c
+++ b/drivers/net/wireless/wl12xx/wl1251_main.c
@@ -375,6 +375,7 @@
static int wl1251_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
{
struct wl1251 *wl = hw->priv;
+ unsigned long flags;
skb_queue_tail(&wl->tx_queue, skb);
@@ -389,16 +390,13 @@
* The workqueue is slow to process the tx_queue and we need stop
* the queue here, otherwise the queue will get too long.
*/
- if (skb_queue_len(&wl->tx_queue) >= WL1251_TX_QUEUE_MAX_LENGTH) {
+ if (skb_queue_len(&wl->tx_queue) >= WL1251_TX_QUEUE_HIGH_WATERMARK) {
wl1251_debug(DEBUG_TX, "op_tx: tx_queue full, stop queues");
- ieee80211_stop_queues(wl->hw);
- /*
- * FIXME: this is racy, the variable is not properly
- * protected. Maybe fix this by removing the stupid
- * variable altogether and checking the real queue state?
- */
+ spin_lock_irqsave(&wl->wl_lock, flags);
+ ieee80211_stop_queues(wl->hw);
wl->tx_queue_stopped = true;
+ spin_unlock_irqrestore(&wl->wl_lock, flags);
}
return NETDEV_TX_OK;