From: "Björn Smedman" <bjorn.smedman@venatech.se>
To: Ben Gamari <bgamari@gmail.com>
Cc: linux-wireless <linux-wireless@vger.kernel.org>,
ath9k-devel@lists.ath9k.org
Subject: Re: [ath9k-devel] ath9k: race conditions in dma
Date: Tue, 2 Nov 2010 17:55:22 +0100 [thread overview]
Message-ID: <AANLkTik+dFEAqGdk9NJpbr8tGKc_NagO8nXSBF4sDtTt@mail.gmail.com> (raw)
In-Reply-To: <8762whrqvm.fsf@gmail.com>
On Mon, Nov 1, 2010 at 4:43 PM, Ben Gamari <bgamari@gmail.com> wrote:
> On Mon, 1 Nov 2010 16:17:23 +0100, Björn Smedman <bjorn.smedman@venatech.se> wrote:
>> Hi all,
>>
>> I have an application that creates and destroys a lot of ap vifs and
>> does a lot of monitor frame injection. The recent ath9k rx locking
>> fixes have helped with stability in this use-case but there still
>> seems to be some tx/beacon related race condition(s). These manifests
>> themselves as follows on an AR913x based router running
>> compat-wireless-2010-10-19 (with locking fixes etc from openwrt):
>>
>> 1. TX DMA hangs under simultaneous high RX and TX load
>> 2. TX is completely hung but chip is never reset
>
> I have also observed both of these behaviors with just a standard
> hostapd single VIF configuration. Quite annoying. It seems to be better
> with recent wireless-testing trees.
>
> - Ben
I just posted "[RFC] ath9k: fix tx queue selection" with a patch that
fixes (or at least reduces) these two for me. I'm not sure it is the
whole story but at least in theory 1 could be caused by locking one tx
queue and actually transmitting on another. 2 is probably caused by
stopping one mac80211 queue and then starting another.
Ben, if you can easily trigger these problems on wireless-testing,
could you test with my patch and see if it helps? I'm especially
interested to see if it really fixes problem 1.
/Björn
WARNING: multiple messages have this Message-ID (diff)
From: "Björn Smedman" <bjorn.smedman@venatech.se>
To: ath9k-devel@lists.ath9k.org
Subject: [ath9k-devel] ath9k: race conditions in dma
Date: Tue, 2 Nov 2010 17:55:22 +0100 [thread overview]
Message-ID: <AANLkTik+dFEAqGdk9NJpbr8tGKc_NagO8nXSBF4sDtTt@mail.gmail.com> (raw)
In-Reply-To: <8762whrqvm.fsf@gmail.com>
On Mon, Nov 1, 2010 at 4:43 PM, Ben Gamari <bgamari@gmail.com> wrote:
> On Mon, 1 Nov 2010 16:17:23 +0100, Bj?rn Smedman <bjorn.smedman@venatech.se> wrote:
>> Hi all,
>>
>> I have an application that creates and destroys a lot of ap vifs and
>> does a lot of monitor frame injection. The recent ath9k rx locking
>> fixes have helped with stability in this use-case but there still
>> seems to be some tx/beacon related race condition(s). These manifests
>> themselves as follows on an AR913x based router running
>> compat-wireless-2010-10-19 (with locking fixes etc from openwrt):
>>
>> 1. TX DMA hangs under simultaneous high RX and TX load
>> 2. TX is completely hung but chip is never reset
>
> I have also observed both of these behaviors with just a standard
> hostapd single VIF configuration. Quite annoying. It seems to be better
> with recent wireless-testing trees.
>
> - Ben
I just posted "[RFC] ath9k: fix tx queue selection" with a patch that
fixes (or at least reduces) these two for me. I'm not sure it is the
whole story but at least in theory 1 could be caused by locking one tx
queue and actually transmitting on another. 2 is probably caused by
stopping one mac80211 queue and then starting another.
Ben, if you can easily trigger these problems on wireless-testing,
could you test with my patch and see if it helps? I'm especially
interested to see if it really fixes problem 1.
/Bj?rn
next prev parent reply other threads:[~2010-11-02 16:55 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-01 15:17 ath9k: race conditions in dma Björn Smedman
2010-11-01 15:17 ` [ath9k-devel] " Björn Smedman
2010-11-01 15:43 ` Ben Gamari
2010-11-01 15:43 ` Ben Gamari
2010-11-01 15:50 ` Björn Smedman
2010-11-01 15:50 ` Björn Smedman
2010-11-01 23:12 ` Peter Stuge
2010-11-01 23:12 ` Peter Stuge
2010-11-01 16:20 ` Björn Smedman
2010-11-01 16:20 ` Björn Smedman
2010-11-01 16:39 ` Björn Smedman
2010-11-01 16:39 ` Björn Smedman
2010-11-01 16:44 ` Luis R. Rodriguez
2010-11-01 16:44 ` Luis R. Rodriguez
2010-11-01 16:52 ` Felix Fietkau
2010-11-01 16:52 ` Felix Fietkau
2010-11-01 17:12 ` Björn Smedman
2010-11-01 17:12 ` Björn Smedman
2010-11-02 16:55 ` Björn Smedman [this message]
2010-11-02 16:55 ` Björn Smedman
2010-11-03 16:41 ` Björn Smedman
2010-11-03 16:41 ` Björn Smedman
2010-11-03 17:47 ` Ben Gamari
2010-11-03 17:47 ` Ben Gamari
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