Re: Future of the SAA7146 drivers

From: Stefan Herdler <herdler@nurfuerspam.de>
To: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	linux-media@vger.kernel.org,
	Manu Abraham <abraham.manu@gmail.com>,
	Tomasz Maciej Nowak <tmn505@gmail.com>,
	Corinna Vinschen <vinschen@redhat.com>,
	Soeren Moch <smoch@web.de>
Subject: Re: Future of the SAA7146 drivers
Date: Mon, 13 Feb 2023 00:10:29 +0100	[thread overview]
Message-ID: <99397771-409b-e487-e429-d5c9feb82209@nurfuerspam.de> (raw)
In-Reply-To: <20230208100847.3ec87576@coco.lan>

On 08/02/23 10:08, Mauro Carvalho Chehab wrote:

[...]

>>> with a big fat notice that
>>> these APIs are now av7110 specific
>> Don't worry there are only the 2 fullfeatured-cards using this API and
>> just because of historical reasons. The driver of the "new"
>> HD-fullfeatured-card dates back to 2008 (*).
>> Meanwhile here have been written several specific output-device-plugins
>> for vdr using V4L-API, vaapi, vdpau, ...
>> There are no plans to use this part of the DVB-API ever again.
>
> Ok. If that's the case, maybe we can just keep the api without changes.
>
> Yet, in order to move av7110 out of staging, we should finish documenting
> the API (or drop the unused/undocumented parts of it).

Hi Mauro,
that sounds like a good plan to me.

Documentation is a solvable problem. At least for the parts used by the
full-featured-cards.
The VDR-plugin-API is pretty well documented (1) and the output-plugin
for the full-featured-cards push most commands right trough.

It is still a laborious task to crosscheck the documents, but most
information should be already there.
I think I'll get it done, but it my take a while depending on my other
duties.

Documenting the "unused" parts could be difficult.
There is no helpful documentation about the "enigma2" receivers. At
least I haven't found some.
This receivers are also not completely open source. The the drivers seem
to be binary only.
The only things I know for sure are: The OSD-part of the DVB-API isn't
used (2) and the audio- and video-part are used (3).
I manged to find the file where the headers are included (4), but there
is no documentation either.

I think I'll start with the used parts and see how far I come.
I'll mail again when I'm done, probably in 2 or 3 weeks.

Thanks and Regards

Stefan

>
>> (* The driver is out-of-tree and doesn't count. It is just about the date.)
>>    (as they have almost always been in
>>> practice).
>
> Thanks,
> Mauro

1.  http://git.tvdr.de/?p=vdr.git;a=blob;f=device.h

2.  https://en.wikipedia.org/wiki/Enigma_(DVB)#Technical_realization
     "direct access to framebuffer"

3.
https://github.com/OpenPLi/openpli-oe-core/blob/10e1dd6b0109ce787dbae204275659778119eafb/meta-openpli/recipes-kernel/linux-libc-headers/linux-libc-headers/audio_video_ioctl.patch

4.  https://github.com/openatv/enigma2/blob/master/lib/dvb/decoder.cpp