Hi Thierry,


On 15/02/2021 10:50, Thierry Reding wrote:
> On Mon, Feb 15, 2021 at 10:10:26AM +0100, Neil Armstrong wrote:
>> Hi,
>>
>> On 13/02/2021 11:15, Mikko Perttunen wrote:
>>> Hi all,
>>>
>>> with the release of documentation headers for Tegra multimedia engines
>>> (NVDEC, NVENC, NVJPG) [1], I have started working on the corresponding
>>> implementations. Here's the first one, NVDEC.
>>>
>>> The kernel driver is a simple Falcon boot driver based on the VIC
>>> driver. Some code sharing should be considered there in the future.
>>> The userspace driver to accompany this is a bit more complicated -
>>> I have expanded vaapi-tegra-driver[2] to support MPEG2 decoding.
>>> It should be noted that the implementation is still very clunky
>>> and has poor performance, but it's a start.
>>
>> Funny how all this tries to avoid all the DRM, remoteproc, V4L2-M2M stateless & co
>> all the other vendors tries to make usage of...
> 
> Care to elaborate why you think this is trying to avoid anything? Mikko
> pointed you at the documentation for these engines, provided a link to
> an open-source (albeit work in progress) userspace driver and posts an
> extension to an existing DRM driver to add the required kernel
> functionality. That's a standard approach for submitting this kind of
> driver.

Thanks for the reply, I didn't look extensively at all the documents & userspace
libraries, but I wonder why this couldn't fit in the V4L2-M2M approach and avoid
having userspace drivers and specific libraries to handle this.

Neil

> 
> Thierry
>