Re: [EXT] Re: [PATCH 0/5] Add V4L2 driver for i.MX8 JPEG Encoder/Decoder

[Mirela Rabulea <mirela.rabulea@nxp.com>]

Hi Hans,

On Vi, 2019-11-08 at 15:06 +0100, Hans Verkuil wrote:
> > Is there a "good example" of a v4l m2m driver that passes these
> vim2m. Also drivers/media/platform/mtk-jpeg/ (although I'm not sure
> when
> it was last tested with v4l2-compliance, so it might be a bit out of
> date).
> 
> > 
> > streaming tests? That would save some time on my side.

Thanks a lot for the examples.
I'm sending _v2 of the patch, with fixes for streaming tests.
One mention here, I dropped the support for USERPTR buffers, based on
this:
https://lwn.net/Articles/447435/
"VB2_USERPTR: buffers allocated in user space. Normally, only devices
which can do scatter/gather I/O can deal with user-space buffers.
Interestingly, videobuf2 supports contiguous buffers allocated by user
space; the only way to get those, though, is to use some sort of
special mechanism like the out-of-tree Android "pmem" driver.
Contiguous I/O to huge pages is not supported."

I wonder if VB2_USERPTR make sense together
with &vb2_dma_contig_memops? I see at least 1 driver with this
combination (s5p-jpeg), I would be surprised if that passes the
streaming tests.

Regards,
Mirela