[PATCH 0/3] NVIDIA Tegra210 NVJPG support

[Diogo Ivo]

On 6/10/25 10:05 AM, Thierry Reding wrote:
> On Fri, Jun 06, 2025 at 11:45:33AM +0100, Diogo Ivo wrote:
>> Hello,
>>
>> This series adds support for the NVJPG hardware accelerator found in the
>> Tegra210 SoC.
>>
>> The kernel driver is essentially a copy of the NVDEC driver as both
>> engines are Falcon-based.
>>
>> For the userspace part I have written a Mesa Gallium backend [1] that,
>> while still very much experimental, works in decoding images with VA-API.
>>
>> I have been using ffmpeg to call VA-API with the following command:
>>
>> ffmpeg -v verbose -hwaccel vaapi -hwaccel_device /dev/dri/renderD129 -i <input.jpg> -pix_fmt bgra -f fbdev /dev/fb0
>>
>> which decodes <input.jpg> and shows the result in the framebuffer.
>>
>> The firmware for the engine can be obtained from a Linux for Tegra
>> distribution.
> 
> By the way, have you tried running this on anything newer than Tegra210?
> Given your progress on this, we can probably start thinking about
> submitting the binaries to linux-firmware.

Since I don't have access to other Tegra platforms I haven't been able
to test this driver there. For this I need help from someone with access
to more hardware, I can send a version that just adds the extra compatibles
and we could see if it works.

As for the firmwares that would be great!

>> Due to the way the Gallium implementation works for Tegra
>> the GPU also needs to be enabled.
> 
> I wonder if maybe we can get rid of this requirement. While it's
> certainly nice to have the GPU enabled, there may be cases where using
> only the other engines may be advantageous. Originally when I had worked
> on VIC, I was looking at how it could be used for compositing without
> getting the GPU involved. That's something that Android devices tend(ed)
> to do because of the power savings that come with it.

Yes I think this is possible to do, it mainly has involves properly
handling the Gallium driver initialization. I'll take a look at it
before submitting the MR for the Gallium driver.

Diogo

> Anyway, not a big deal, depending on the GPU for now is fine.