From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nbd.name ([88.198.39.176]:45849 "EHLO ds10.nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753336Ab0BKRH3 (ORCPT ); Thu, 11 Feb 2010 12:07:29 -0500 Message-ID: <4B743947.5070303@openwrt.org> Date: Thu, 11 Feb 2010 18:07:19 +0100 From: Felix Fietkau MIME-Version: 1.0 To: linux-wireless CC: "John W. Linville" , "Luis R. Rodriguez" , Jouni Malinen Subject: [PATCH] ath9k: add a workaround for ack timeout issues Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- --- a/drivers/net/wireless/ath/ath9k/hw.c +++ b/drivers/net/wireless/ath/ath9k/hw.c @@ -1233,6 +1233,17 @@ void ath9k_hw_init_global_settings(struc /* 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);