[PATCH] drm/rockchip: support prime fd import

[Emil Velikov]

On 23 February 2016 at 23:56, Rob Clark <robdclark at gmail.com> wrote:
> On Tue, Feb 23, 2016 at 6:29 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>> Hi Zach,
>>
>> On 2 February 2016 at 23:37, Zach Reizner <zachr at google.com> wrote:
>>> The prime fd to handle ioctl was not used with rockchip before. Support
>>> was added in order to support potential uses (e.g. zero-copy video
>>> decode, camera).
>>>
>> Similar patch came around a few months ago and got this reply [1]. If
>> the situation has changed (there is an open-source driver/user for
>> this) it should be clearly mentioned in the commit message, as opposed
>> to "in order to support potential uses".
>
> hmm, well it is not driver specific uabi, and we have let several
> other mali/img users do prime..
>
I'm suspecting that's because we missed the patches fly by, as opposed
to people being particularly happy with the idea. If the "don't break
userspace" kernel rule did not exist and a few more people to kept an
eye open for these misuses [I believe is the correct word], things
could easily be fixed/reverted ;-)

If the majority feels like we can/should allow these - so be it. I'm
just pointing/reminding what was said previously.

> I'm not sure, maybe those platforms can do a basic v4l <-> display
> thing w/ prime.  Although upstream tends to hurt a bit for camera
> support..
>
It a bit unfortunate indeed. I wonder if companies cannot put more
pressure on vendors to get things open/upstream - hint, hint ;-)

Wanted: Dead or alive - [upstream] open-source users :-P

Regards
Emil