[Intel-gfx] [PATCH] drm/core: Change declaration for gamma_set.

[Emil Velikov]

On 6 June 2016 at 17:15, Maarten Lankhorst
<maarten.lankhorst at linux.intel.com> wrote:
> Op 06-06-16 om 18:11 schreef Emil Velikov:
>> On 6 June 2016 at 17:00, Daniel Vetter <daniel at ffwll.ch> wrote:
>>> On Mon, Jun 06, 2016 at 11:18:09AM +0200, Maarten Lankhorst wrote:
>>>> Change return value to int to propagate errors from gamma_set,
>>>> and remove start parameter. Updates always use the full size,
>>>> and some drivers even ignore the start parameter altogether.
>>> Commit message should explain why we suddenly need to pass up the error
>>> code, too:
>>>
>>> "This is needed for atomic drivers, where an atomic commit can fail with
>>> EAGAIN and should be restarted."
>>>
>> Since that can happen only on the DRM core side, shouldn't one refrain
>> from adding the "always returns 0" return status for the drivers'
>> .gamma_set hook ? Or there's is something in the works that would lead
>> to drivers being able to return a non 0 value ?
> Look at drm_atomic_helper.c :-)
>
> Being implemented as an atomic update means any errno can be returned.
>
Ouch. Looks like only the i915 driver uses the helper while I was
looking at other ATOMIC drivers. So things short circuited on my
noggin'. I guess it's up-to the respective drivers to be updated and
use the drm_atomic_helper_legacy_gamma_set helper.

Thanks for sticking with my silly question :-)
Emil