[PATCH 3.13 109/259] mwifiex: fix Tx timeout issue

[Kamal Mostafa]

3.13.11.6 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Amitkumar Karwar <akarwar at marvell.com>

commit d76744a93246eccdca1106037e8ee29debf48277 upstream.

https://bugzilla.kernel.org/show_bug.cgi?id=70191
https://bugzilla.kernel.org/show_bug.cgi?id=77581

It is observed that sometimes Tx packet is downloaded without
adding driver's txpd header. This results in firmware parsing
garbage data as packet length. Sometimes firmware is unable
to read the packet if length comes out as invalid. This stops
further traffic and timeout occurs.

The root cause is uninitialized fields in tx_info(skb->cb) of
packet used to get garbage values. In this case if
MWIFIEX_BUF_FLAG_REQUEUED_PKT flag is mistakenly set, txpd
header was skipped. This patch makes sure that tx_info is
correctly initialized to fix the problem.

Reported-by: Andrew Wiley <wiley.andrew.j at gmail.com>
Reported-by: Linus Gasser <list at markas-al-nour.org>
Reported-by: Michael Hirsch <hirsch at teufel.de>
Tested-by: Xinming Hu <huxm at marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar at marvell.com>
Signed-off-by: Maithili Hinge <maithili at marvell.com>
Signed-off-by: Avinash Patil <patila at marvell.com>
Signed-off-by: Bing Zhao <bzhao at marvell.com>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/mwifiex/main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/mwifiex/main.c b/drivers/net/wireless/mwifiex/main.c
index 8bb8988..a5c00cc 100644
--- a/drivers/net/wireless/mwifiex/main.c
+++ b/drivers/net/wireless/mwifiex/main.c
@@ -646,6 +646,7 @@ mwifiex_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	tx_info = MWIFIEX_SKB_TXCB(skb);
+	memset(tx_info, 0, sizeof(*tx_info));
 	tx_info->bss_num = priv->bss_num;
 	tx_info->bss_type = priv->bss_type;
 
-- 
1.9.1