linux-kernel - Re: [Patch v2] ALSA: compress: allow to leave draining state when pausing in draining

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:   Thu, 8 Jul 2021 16:53:20 +0200
From:   Jaroslav Kysela <perex@...ex.cz>
To:     Robert Lee <lerobert@...gle.com>, Takashi Iwai <tiwai@...e.de>
Cc:     vkoul@...nel.org, tiwai@...e.com, alsa-devel@...a-project.org,
        linux-kernel@...r.kernel.org, carterhsu@...gle.com,
        zxinhui@...gle.com, bubblefang@...gle.com
Subject: Re: [Patch v2] ALSA: compress: allow to leave draining state when
 pausing in draining

On 08. 07. 21 15:47, Robert Lee wrote:
> Hi Takashi,
> 
> It is a little complex to describe the design in detail, but try to
> explain simply
> what issue we meet.
> 
> If w/o the change,  after user resumes from the pause, our system would call
> snd_compr_drain() or snd_compr_partial_drain() again after it returns from
> previous drain (when EOF reaches). Then it will block in this drain and no one
> wake it up because EOF has already reached. I add this change to return from
> the previous drain.

It looks like that the driver does not call snd_compr_drain_notify() so the
state is not updated to SETUP on EOF.

> Actually, I am wondering how the pause-during-drain can keep the state in
> DRAINING. It should have a different design. :)

I already proposed to add a new state (because it's a new state), but the
conservative way was elected to avoid user space changes.

				Jaroslav

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