linux-kernel - Re: [PATCH v2 1/1] ASoC: soc-pcm.c: Make sure DAI parameters cleared if the DAI becomes inactive

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] [day] [month] [year] [list]

Message-ID: <ZWRTZLi9SqarEUXa@hovoldconsulting.com>
Date:   Mon, 27 Nov 2023 09:29:24 +0100
From:   Johan Hovold <johan@...nel.org>
To:     Chancel Liu <chancel.liu@....com>
Cc:     lgirdwood@...il.com, broonie@...nel.org, perex@...ex.cz,
        tiwai@...e.com, alsa-devel@...a-project.org,
        linux-kernel@...r.kernel.org,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Subject: Re: [PATCH v2 1/1] ASoC: soc-pcm.c: Make sure DAI parameters cleared
 if the DAI becomes inactive

On Wed, Sep 20, 2023 at 11:36:21PM +0800, Chancel Liu wrote:
> The commit 1da681e52853 ("ASoC: soc-pcm.c: Clear DAIs parameters after
> stream_active is updated") tries to make sure DAI parameters can be
> cleared properly through moving the cleanup to the place where stream
> active status is updated. However, it will cause the cleanup only
> happening in soc_pcm_close().
> 
> Suppose a case: aplay -Dhw:0 44100.wav 48000.wav. The case calls
> soc_pcm_open()->soc_pcm_hw_params()->soc_pcm_hw_free()->
> soc_pcm_hw_params()->soc_pcm_hw_free()->soc_pcm_close() in order. The
> parameters would be remained in the system even if the playback of
> 44100.wav is finished.
> 
> The case requires us clearing parameters in phase of soc_pcm_hw_free().
> However, moving the DAI parameters cleanup back to soc_pcm_hw_free()
> has the risk that DAIs parameters never be cleared if there're more
> than one stream, see commit 1da681e52853 ("ASoC: soc-pcm.c: Clear DAIs
> parameters after stream_active is updated") for more details.
> 
> To meet all these requirements, in addition to do DAI parameters
> cleanup in soc_pcm_hw_free(), also check it in soc_pcm_close() to make
> sure DAI parameters cleared if the DAI becomes inactive.
> 
> Fixes: 1da681e52853 ("ASoC: soc-pcm.c: Clear DAIs parameters after stream_active is updated")
> Signed-off-by: Chancel Liu <chancel.liu@....com>

For the record, this change incidentally also fixed the remaining click
sounds I heard when stopping pulseaudio (e.g. on reboot) with the Lenovo
ThinkPad X13s, which have also been discussed here:

	https://lore.kernel.org/lkml/ZTukaxUhgY4WLgEs@hovoldconsulting.com/

Johan