[PATCH 2/2] drm: Add new driver for MXSFB controller

[Marek Vasut]

On 09/26/2016 02:11 PM, Daniel Vetter wrote:
> On Mon, Sep 26, 2016 at 12:36 PM, Marek Vasut <marex at denx.de> wrote:
>>>>>> +
>>>>>> +static int mxsfb_atomic_commit(struct drm_device *dev,
>>>>>> +                           struct drm_atomic_state *state, bool nonblock)
>>>>>> +{
>>>>>> +    return drm_atomic_helper_commit(dev, state, false);
>>>>>
>>>>> Atomic helpers support async commit nowadays, no need any more for this
>>>>> hack.
>>>>
>>>> I had to add the same fence check as imx drm driver, so this function
>>>> grew in V2.
>>>
>>> Please check out my reply to Lucas patch. tldr: The fence check should
>>> be done in prepare_fb plane hook, and we should have one
>>> implementation in the cma fb helper library for all drivers. Would be
>>> great if you could create that helper (and switch imx over to it).
>>
>> Done, although what I did might be wrong. I will submit the patches once
>> I am a bit more confident about that. I have a question -- should the
>> drm simple kms helper code be augmented with a new parameter to add
>> this prepare_fb helper into the plane helper functions or should the
>> drm simple kms helper always call the prepare_fb with the fence part ?
> 
> Great question, not sure what the answer should be tbh. Maybe we need
> to wire up prepare_fb/cleanup_fb for simple drm? I think forcing a
> default hook of using cma isn't a good idea, since e.g. udl would be a
> perfect candidate for simple drm helpers, but that wants plain shmem
> gem buffers, not cma gem buffers. Means a notch more boilerplate for
> drivers (1 line in the vtable), but I think that's ok.
> -Daniel

OK, makes sense, done.

-- 
Best regards,
Marek Vasut