linux-kernel - Re: [alsa-devel] [PATCH] ASoC: soc-pcm: Use delay set in pointer function

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]

Message-ID: <s5heffjr8ys.wl-tiwai@suse.de>
Date:   Tue, 31 Jul 2018 12:32:59 +0200
From:   Takashi Iwai <tiwai@...e.de>
To:     Mark Brown <broonie@...nel.org>
Cc:     "Agrawal, Akshu" <Akshu.Agrawal@....com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        "moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM..." 
        <alsa-devel@...a-project.org>, Alexander.Deucher@....com,
        djkurtz@...omium.org, Liam Girdwood <lgirdwood@...il.com>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [alsa-devel] [PATCH] ASoC: soc-pcm: Use delay set in pointer function

On Tue, 31 Jul 2018 12:19:43 +0200,
Mark Brown wrote:
> 
> On Tue, Jul 31, 2018 at 11:25:11AM +0200, Takashi Iwai wrote:
> 
> > It's not necessary that all CPU dais provide the pointer callback.
> > My suggestion is that, if CPU dai *wants* to provide the base delay,
> > it must be tied with the position value, hence it should provide the
> > pointer callback.  If CPU dai has a pointer callback,
> > snd_soc_pcm_pointer() skips the component pointer callback but uses
> > CPU dai pointer callback instead.
> 
> However since it's not supposed to be providing any DMA a CPU DAI really
> shouldn't be doing this...

Well, if so, the CPU dai also cannot get the exact base delay
corresponding to the reported position, either, no?


Takashi