linux-kernel - Re: [PATCH] soundwire: cadence: fix race condition between suspend and Slave device alerts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3e4dee4b-1309-2d3e-ae20-e2dcbadb2f40@perex.cz>
Date:   Tue, 8 Sep 2020 13:58:33 +0200
From:   Jaroslav Kysela <perex@...ex.cz>
To:     Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Vinod Koul <vkoul@...nel.org>
Cc:     alsa-devel@...a-project.org, tiwai@...e.de,
        gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
        ranjani.sridharan@...ux.intel.com, hui.wang@...onical.com,
        broonie@...nel.org, srinivas.kandagatla@...aro.org,
        jank@...ence.com, mengdong.lin@...el.com, sanyog.r.kale@...el.com,
        Bard Liao <yung-chuan.liao@...ux.intel.com>,
        rander.wang@...ux.intel.com, bard.liao@...el.com
Subject: Re: [PATCH] soundwire: cadence: fix race condition between suspend
 and Slave device alerts

Dne 28. 08. 20 v 17:14 Pierre-Louis Bossart napsal(a):
> 
> 
> 
>> Is this timeout for suspend or resume? Somehow I was under the
>> assumption that it is former? Or is the result seen on resume?
>>
>> Rereading the race describe above in steps, I think this should be
>> handled in step c above. Btw is that suspend or runtime suspend which
>> causes this? Former would be bigger issue as we should not have work
>> running when we return from suspend call. Latter should be dealt with
>> anyway as device might be off after suspend.
> 
> This happens with a system suspend. Because we disable the interrupts, 
> the workqueue never completes, and we have a timeout on system resume.
> 
> That's why we want to prevent the workqueue from starting, or let it 
> complete, but not have this zombie state where we suspend but there's 
> still a wait for completion that times out later. The point here is 
> really  making sure the workqueue is not used before suspend.
> 

Vinod, there is no acceptance progress on this. The patch is really straight
and for the Intel controller. They know what they're doing. I would apply
this. The code can be refined at anytime. It's a fix. I tested it and I can
confirm, that it fixes the issue. It's a vital patch for 5.10 to enable
finally SoundWire drivers for the Intel hardware.

Acked-by: Jaroslav Kysela <perex@...ex.cz>


-- 
Jaroslav Kysela <perex@...ex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.