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Date: Mon, 1 Jun 2015 10:27:49 +0200
Message-ID: <CA+BoTQmmm6NA2Lb5TB9rSiXYWWarGLGaE5KFJW0_aaqz1YwR3g@mail.gmail.com> (sfid-20150601_102809_033858_3B89CC82)
Subject: Re: system hang with backports-20150511/20150525
From: Michal Kazior <michal.kazior@tieto.com>
To: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Marty Faltesek <mfaltesek@google.com>,
	Martin Faltesek <martin.faltesek@gmail.com>,
	linux-wireless <linux-wireless@vger.kernel.org>,
	"ath10k@lists.infradead.org" <ath10k@lists.infradead.org>
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On 1 June 2015 at 09:13, Kalle Valo <kvalo@qca.qualcomm.com> wrote:
> Michal Kazior <michal.kazior@tieto.com> writes:
>
>> +ath10k list
>>
>> On 1 June 2015 at 03:37, Marty Faltesek <mfaltesek@google.com> wrote:
>>> Starting with backports-20150511, and continuing with
>>> backports-20150525, we see frequent system hangs. backports-20150424
>>> had no issue.
>>
>> I don't see such binary releases on
>> https://backports.wiki.kernel.org/index.php/Main_Page
>> Hence I don't know what kernel you've backported the drivers from and
>> I can't compare anything.
>>
>> Can you provide more details, please?
>
> I suspect it's from here:
>
> https://www.kernel.org/pub/linux/kernel/projects/backports/2015/05/25/
>
> The backports project pages are a bit confusing and that location is
> hard to find.

Oh, thanks!

Hmm.. There was a ton of changes between 20150424 and 20150511. For
one, ath10k started to use chanctx API and FAST_XMIT. But it's not a
given these two are to blame.

The latter can be easily disabled by removing
IEEE80211_HW_SUPPORT_FAST_XMIT from ar->hw->flags in ath10k's mac.c.
The former.. not so easy. I'd be awesome if you could do a git bisect.
The commit ids are a3da0fb6(good) f17107c(bad) (you need linux-next
git repo including its tags for these ids to be resolvable).


Michał