From: Mauro Carvalho Chehab <mchehab@kernel.org>
To: Mark Brown <broonie@kernel.org>
Cc: nicoleotsuka@gmail.com, alsa-devel@alsa-project.org,
lgirdwood@gmail.com,
Sebastian Fricke <sebastian.fricke@collabora.com>,
Xiubo.Lee@gmail.com, festevam@gmail.com,
Shengjiu Wang <shengjiu.wang@nxp.com>,
tiwai@suse.com, linux-kernel@vger.kernel.org, tfiga@chromium.org,
hverkuil@xs4all.nl, linuxppc-dev@lists.ozlabs.org,
sakari.ailus@iki.fi, perex@perex.cz, linux-media@vger.kernel.org,
shengjiu.wang@gmail.com, m.szyprowski@samsung.com
Subject: Re: [PATCH v15 00/16] Add audio support in v4l2 framework
Date: Tue, 30 Apr 2024 17:27:52 +0100 [thread overview]
Message-ID: <20240430172752.20ffcd56@sal.lan> (raw)
In-Reply-To: <ZjEEKyvb02CWz3l4@finisterre.sirena.org.uk>
Em Tue, 30 Apr 2024 23:46:03 +0900
Mark Brown <broonie@kernel.org> escreveu:
> On Tue, Apr 30, 2024 at 10:21:12AM +0200, Sebastian Fricke wrote:
>
> > first of all thanks for all of this work and I am very sorry for only
> > emerging this late into the series, I sadly didn't notice it earlier.
>
> It might be worth checking out the discussion on earlier versions...
>
> > 1. The biggest objection is, that the Linux Kernel has a subsystem
> > specifically targeted for audio devices, adding support for these
> > devices in another subsystem are counterproductive as they work around
> > the shortcomings of the audio subsystem while forcing support for a
> > device into a subsystem that was never designed for such devices.
> > Instead, the audio subsystem has to be adjusted to be able to support
> > all of the required workflows, otherwise, the next audio driver with
> > similar requirements will have to move to the media subsystem as well,
> > the audio subsystem would then never experience the required change and
> > soon we would have two audio subsystems.
>
> The discussion around this originally was that all the audio APIs are
> very much centered around real time operations rather than completely
> async memory to memory operations and that it's not clear that it's
> worth reinventing the wheel simply for the sake of having things in
> ALSA when that's already pretty idiomatic for the media subsystem. It
> wasn't the memory to memory bit per se, it was the disconnection from
> any timing.
The media subsystem is also centered around real time. Without real
time, you can't have a decent video conference system. Having
mem2mem transfers actually help reducing real time delays, as it
avoids extra latency due to CPU congestion and/or data transfers
from/to userspace.
>
> > So instead of hammering a driver into the wrong destination, I would
> > suggest bundling our forces and implementing a general memory-to-memory
> > framework that both the media and the audio subsystem can use, that
> > addresses the current shortcomings of the implementation and allows you
> > to upload the driver where it is supposed to be.
>
> That doesn't sound like an immediate solution to maintainer overload
> issues... if something like this is going to happen the DRM solution
> does seem more general but I'm not sure the amount of stop energy is
> proportionate.
I don't think maintainer overload is the issue here. The main
point is to avoid a fork at the audio uAPI, plus the burden
of re-inventing the wheel with new codes for audio formats,
new documentation for them, etc.
Regards,
Mauro
next prev parent reply other threads:[~2024-04-30 16:28 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-19 7:50 [PATCH v15 00/16] Add audio support in v4l2 framework Shengjiu Wang
2024-03-19 7:50 ` [PATCH v15 01/16] media: v4l2-ctrls: add support for fraction_bits Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 02/16] ASoC: fsl_asrc: define functions for memory to memory usage Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 03/16] ASoC: fsl_easrc: " Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 04/16] ASoC: fsl_asrc: move fsl_asrc_common.h to include/sound Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 05/16] ASoC: fsl_asrc: register m2m platform device Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 06/16] ASoC: fsl_easrc: " Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 07/16] media: uapi: Add V4L2_CAP_AUDIO_M2M capability flag Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 08/16] media: v4l2: Add audio capture and output support Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 09/16] media: uapi: Define audio sample format fourcc type Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 10/16] media: uapi: Add V4L2_CTRL_CLASS_M2M_AUDIO Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 11/16] media: uapi: Add audio rate controls support Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 12/16] media: uapi: Declare interface types for Audio Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 13/16] media: uapi: Add an entity type for audio resampler Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 14/16] media: vivid: add fixed point test controls Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 15/16] media: imx-asrc: Add memory to memory driver Shengjiu Wang
2024-03-19 7:51 ` [PATCH v15 16/16] media: vim2m-audio: add virtual driver for audio memory to memory Shengjiu Wang
[not found] ` <20240430082112.jrovosb6lgblgpfg@basti-XPS-13-9310>
2024-04-30 8:47 ` [PATCH v15 00/16] Add audio support in v4l2 framework Hans Verkuil
2024-04-30 13:52 ` Mauro Carvalho Chehab
2024-04-30 14:46 ` Mark Brown
2024-04-30 15:03 ` Jaroslav Kysela
2024-04-30 16:27 ` Mauro Carvalho Chehab [this message]
2024-05-01 1:56 ` Mark Brown
2024-05-02 7:46 ` Takashi Iwai
2024-05-02 8:59 ` Mauro Carvalho Chehab
2024-05-02 9:26 ` Mauro Carvalho Chehab
2024-05-03 1:47 ` Mark Brown
2024-05-03 8:42 ` Mauro Carvalho Chehab
2024-05-06 8:49 ` Shengjiu Wang
2024-05-06 9:42 ` Jaroslav Kysela
2024-05-08 8:00 ` Hans Verkuil
2024-05-08 8:13 ` Amadeusz Sławiński
2024-05-09 9:36 ` Shengjiu Wang
2024-05-09 9:50 ` Amadeusz Sławiński
2024-05-09 10:12 ` Shengjiu Wang
2024-05-09 10:28 ` Amadeusz Sławiński
2024-05-09 10:44 ` Shengjiu Wang
2024-05-09 11:13 ` Jaroslav Kysela
2024-05-13 11:56 ` Jaroslav Kysela
2024-05-15 9:17 ` Hans Verkuil
2024-05-15 9:50 ` Jaroslav Kysela
2024-05-15 10:19 ` Takashi Iwai
2024-05-15 10:46 ` Jaroslav Kysela
2024-05-15 13:34 ` Shengjiu Wang
2024-05-16 14:58 ` Jaroslav Kysela
2024-05-15 20:33 ` Nicolas Dufresne
2024-05-16 14:50 ` Jaroslav Kysela
2024-05-27 7:24 ` Jaroslav Kysela
2024-05-15 14:04 ` Pierre-Louis Bossart
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