mwifiex: Trigger a card reset on reaching tx_timeout threshold

tx_timeout doesn't always lead to a cmd_timeout. There are
occurrences where cmd_timeout never gets triggered for a long
time and we encounter a kernel crash. In this patch, we track
the consecutive timeouts (tx_timeout_cnt). When tx_timeout_cnt
exceeds the threshold, trigger a card reset thereby avoiding a
kernel crash.

Signed-off-by: Ashok Nagarajan <asnagarajan@chromium.org>
Signed-off-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/txrx.c b/drivers/net/wireless/mwifiex/txrx.c
index 296faec..8f923d0 100644
--- a/drivers/net/wireless/mwifiex/txrx.c
+++ b/drivers/net/wireless/mwifiex/txrx.c
@@ -169,6 +169,8 @@
 	if (!status) {
 		priv->stats.tx_packets++;
 		priv->stats.tx_bytes += skb->len;
+		if (priv->tx_timeout_cnt)
+			priv->tx_timeout_cnt = 0;
 	} else {
 		priv->stats.tx_errors++;
 	}