[ath9k-devel] FYI: "Failed to stop TX DMA!" not fixed in kernel 3.6.7

From: Alexander Szlezak <alex@szlezak.com>
To: ath9k-devel@lists.ath9k.org
Subject: [ath9k-devel] FYI: "Failed to stop TX DMA!" not fixed in kernel 3.6.7
Date: Tue, 20 Nov 2012 23:46:18 +0100	[thread overview]
Message-ID: <50AC083A.7050101@szlezak.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1211210204280.8668@icf.org.ru>

Hi,

I can confirm this too. It exists in master mode too in recent trunk 
(later than the version which is referred to as possible fix in trac), 
we experienced it especially when using 3 vaps in master mode. Once it 
occurs all clients hang. I'm willing to support a fix - let me know more 
what is needed.

best,
Alexander

Am 20.11.2012 23:04, schrieb Georgiewskiy Yuriy:
> On 2012-11-19 19:33 -0000, Chaoxing Lin wrote linux-wireless at vger.kernel.or...:
>
> Hi all, i can confim this, "Failed to stop TX DMA!" steel exists in 802.11s and other modes too,
> i use many different cards but all ar9002 based.
>
> CL>Just FYI
> CL>
> CL>Kernel 3.6.7 change log says "This patch might fix crashes and "Failed to stop TX DMA!" messages."
> CL>
> CL>I tried it on Dell laptop with ar9390 radio.
> CL>Still, I got error message like below
> CL>
> CL>"ath: phy0: Failed to stop TX DMA, queues=0x005!"
> CL>"ath: phy0: Failed to stop TX DMA, queues=0x001!"
> CL>
> CL>I am testing 802.11s mesh on 802.11a channel 40, no HT enabled.
> CL>
> CL>
> CL>-----------------------------
> CL>
> CL>commit cd585fb70b89fb57f8dffb03a2a72c30f81f5da6
> CL>Author: Felix Fietkau <nbd@openwrt.org>
> CL>Date:   Fri Oct 26 00:31:11 2012 +0200
> CL>
> CL>    ath9k: fix stale pointers potentially causing access to free'd skbs
> CL>
> CL>    commit 8c6e30936a7893a85f6222084f0f26aceb81137a upstream.
> CL>
> CL>    bf->bf_next is only while buffers are chained as part of an A-MPDU
> CL>    in the tx queue. When a tid queue is flushed (e.g. on tearing down
> CL>    an aggregation session), frames can be enqueued again as normal
> CL>    transmission, without bf_next being cleared. This can lead to the
> CL>    old pointer being dereferenced again later.
> CL>
> CL>    This patch might fix crashes and "Failed to stop TX DMA!" messages.
> CL>
> CL>    Signed-off-by: Felix Fietkau <nbd@openwrt.org>
> CL>    Signed-off-by: John W. Linville <linville@tuxdriver.com>
> CL>    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> CL>_______________________________________________
> CL>ath9k-devel mailing list
> CL>ath9k-devel at lists.ath9k.org
> CL>https://lists.ath9k.org/mailman/listinfo/ath9k-devel
> CL>
>
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