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authorFelix Fietkau <nbd@openwrt.org>2010-02-11 20:07:19 +0300
committerJohn W. Linville <linville@tuxdriver.com>2010-02-12 22:28:40 +0300
commit42c4568a4ace0adc27a9d6f02936e2047ba6fc7e (patch)
treebe0b60ad408401fd2449d87ca1d380731f0dcbf0 /drivers
parent4cad6c7c38930618d77e65af82c1403d63879eee (diff)
downloadlinux-42c4568a4ace0adc27a9d6f02936e2047ba6fc7e.tar.xz
ath9k: add a workaround for ack timeout issues
Adding support for setting the coverage class in some cases broke association and data transfer, as it overwrote the initial ACK timeout value from the initvals with a smaller value. I don't know why the new value works in 5 GHz (matches the initval there), but not in 2.4 GHz (initvals use 64us here), so until the problem is fully understood, the value should be increased again. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/wireless/ath/ath9k/hw.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index f15fee76a4e2..f00f5c744f48 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1217,6 +1217,17 @@ void ath9k_hw_init_global_settings(struct ath_hw *ah)
/* As defined by IEEE 802.11-2007 17.3.8.6 */
slottime = ah->slottime + 3 * ah->coverage_class;
acktimeout = slottime + sifstime;
+
+ /*
+ * Workaround for early ACK timeouts, add an offset to match the
+ * initval's 64us ack timeout value.
+ * This was initially only meant to work around an issue with delayed
+ * BA frames in some implementations, but it has been found to fix ACK
+ * timeout issues in other cases as well.
+ */
+ if (conf->channel && conf->channel->band == IEEE80211_BAND_2GHZ)
+ acktimeout += 64 - sifstime - ah->slottime;
+
ath9k_hw_setslottime(ah, slottime);
ath9k_hw_set_ack_timeout(ah, acktimeout);
ath9k_hw_set_cts_timeout(ah, acktimeout);