[059/272] ath9k: Fix bug in delimiter padding computation

Greg KH
2011-02-16T01:43:29Z

From: Vasanthakumar Thiagarajan <vasanth@atheros.com>

commit 39ec2997c374b528cdbf65099b6d6b8593a67f7f upstream.

There is a roundng error in delimiter padding computation
which causes severe throughput drop with some of AR9003.

signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/wireless/ath/ath9k/ath9k.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -178,8 +178,8 @@ void ath_descdma_cleanup(struct ath_soft

/* returns delimiter padding required given the packet length */
#define ATH_AGGR_GET_NDELIM(_len) \
- (((((_len) + ATH_AGGR_DELIM_SZ) < ATH_AGGR_MINPLEN) ? \
- (ATH_AGGR_MINPLEN - (_len) - ATH_AGGR_DELIM_SZ) : 0) >> 2)
+ (((_len) >= ATH_AGGR_MINPLEN) ? 0 : \
+ DIV_ROUND_UP(ATH_AGGR_MINPLEN - (_len), ATH_AGGR_DELIM_SZ))

#define BAW_WITHIN(_start, _bawsz, _seqno) \
((((_seqno) - (_start)) & 4095) < (_bawsz))