[PATCH 3.18 059/185] mac80211: round IEEE80211_TX_STATUS_HEADROOM up to multiple of 4

[Greg Kroah-Hartman]

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

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

From: Felix Fietkau <nbd@xxxxxxxx>

[ Upstream commit 651b9920d7a694ffb1f885aef2bbb068a25d9d66 ]

This ensures that mac80211 allocated management frames are properly
aligned, which makes copying them more efficient.
For instance, mt76 uses iowrite32_copy to copy beacon frames to beacon
template memory on the chip.
Misaligned 32-bit accesses cause CPU exceptions on MIPS and should be
avoided.

Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/net/mac80211.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3368,7 +3368,7 @@ static inline int ieee80211_sta_ps_trans
  * The TX headroom reserved by mac80211 for its own tx_status functions.
  * This is enough for the radiotap header.
  */
-#define IEEE80211_TX_STATUS_HEADROOM	14
+#define IEEE80211_TX_STATUS_HEADROOM	ALIGN(14, 4)
 
 /**
  * ieee80211_sta_set_buffered - inform mac80211 about driver-buffered frames