Return-path: Received: from nbd.name ([46.4.11.11]:44285 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756151Ab2BBOWd (ORCPT ); Thu, 2 Feb 2012 09:22:33 -0500 Message-ID: <4F2A9C26.5070201@openwrt.org> (sfid-20120202_152236_276666_414C673A) Date: Thu, 02 Feb 2012 15:22:30 +0100 From: Felix Fietkau MIME-Version: 1.0 To: =?UTF-8?B?TWFydGluIEh1bmRlYsO4bGw=?= CC: Seth Forshee , linux-wireless@vger.kernel.org, "Luis R. Rodriguez" , Jouni Malinen , Vasanthakumar Thiagarajan , Senthil Balasubramanian Subject: Re: CTS timeout issue with AR9285 References: <20120202042521.GA20635@ubuntu-macmini> <4F2A830A.8000905@openwrt.org> <4F2A9A9D.4000108@gmail.com> In-Reply-To: <4F2A9A9D.4000108@gmail.com> Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2012-02-02 3:15 PM, Martin Hundebøll wrote: > Hi Felix, > > On 2012-02-02 13:35, Felix Fietkau wrote: >> Please try this patch: >> >> --- a/drivers/net/wireless/ath/ath9k/hw.c >> +++ b/drivers/net/wireless/ath/ath9k/hw.c >> @@ -1061,13 +1061,16 @@ void ath9k_hw_init_global_settings(struc >> >> /* >> * Workaround for early ACK timeouts, add an offset to match the >> - * initval's 64us ack timeout value. >> + * initval's 64us ack timeout value. Use 48us for the CTS timeout. >> * 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) >> + if (conf->channel&& conf->channel->band == IEEE80211_BAND_2GHZ) { >> acktimeout += 64 - sifstime - ah->slottime; >> + ctstimeout += 48 - sifstime - ah->slottime; >> + } >> + >> >> ath9k_hw_set_sifs_time(ah, sifstime); >> ath9k_hw_setslottime(ah, slottime); > > I have been seeing the same issues with the Atheros 9170 USB chipset > using the carl9170 driver and firmware, where RST are transmitted > repeatidly, even though a CTS-reply is seen on the air. I suspect the > issue to be related to this one, but I am unable to locate any > calculation or setting of CTS timeout in the driver or firmware. > > Can anyone point me in the right direction to tune the CTS timeout > with the 9170 chip? I think your carl9170 CTS issue is likely to be something else, since AR9170 is using a completely different 802.11 MAC (Zydas design instead of Atheros). - Felix