Re: [PATCH v3] media: venus: amend buffer size for bitstream plane

From: Stanimir Varbanov
Date: Mon Nov 26 2018 - 09:57:45 EST

Hi Hans,

On 11/26/18 3:37 PM, Hans Verkuil wrote:
> On 11/26/2018 11:12 AM, Malathi Gottam wrote:
>> Accept the buffer size requested by client and compare it
>> against driver calculated size and set the maximum to
>> bitstream plane.
>> Signed-off-by: Malathi Gottam <mgottam@xxxxxxxxxxxxxx>
> Sorry, this isn't allowed. It is the driver that sets the sizeimage value,
> never the other way around.

I think for decoders (OUTPUT queue) and encoders (CAPTURE queue) we
allowed userspace to set sizeimage for buffers. See [1] Initialization
paragraph point 2:

desired size of ``CAPTURE`` buffers; the encoder may adjust it to
match hardware requirements

Similar patch we be needed for decoder as well.

> If you need to allocate larger buffers, then use VIDIOC_CREATE_BUFS instead
> What problem are you trying to solve with this patch?
> Regards,
> Hans