Re: [PATCH 2/2] drm: rcar-du: Enable alpha property on primary planes

[Kieran Bingham]

Hi Laurent,

On 21/11/2018 18:29, Laurent Pinchart wrote:
> Hi Kieran,
> 
> On Thursday, 20 September 2018 14:22:38 EET Laurent Pinchart wrote:
>> On Wednesday, 19 September 2018 18:56:59 EEST Kieran Bingham wrote:
>>> If the alpha property is not added to a plane, a default value will be
>>> used, which can result in a non-visible layer if the alpha is
>>> initialised as 0.
>>>
>>> Provide an alpha blend property on all planes.
>>>
>>> Fixes: 161ad653d6c9 ("drm: rcar-du: Use __drm_atomic_helper_plane_reset
>>> instead of copying the logic")
>>>
>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>>> ---
>>>
>>>  drivers/gpu/drm/rcar-du/rcar_du_plane.c | 7 ++++++-
>>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_plane.c
>>> b/drivers/gpu/drm/rcar-du/rcar_du_plane.c index 9e07758a755c..72399a19d8a6
>>> 100644
>>> --- a/drivers/gpu/drm/rcar-du/rcar_du_plane.c
>>> +++ b/drivers/gpu/drm/rcar-du/rcar_du_plane.c
>>> @@ -783,13 +783,18 @@ int rcar_du_planes_init(struct rcar_du_group *rgrp)
>>>
>>>  		drm_plane_helper_add(&plane->plane,
>>>  		
>>>  				     &rcar_du_plane_helper_funcs);
>>>
>>> +		/*
>>> +		 * The alpha property needs to be initialised on all planes
>>> +		 * to ensure the correct setting at the output.
>>> +		 */
>>> +		drm_plane_create_alpha_property(&plane->plane);
>>> +
>>
>> As mentioned in the cover letter, both patches in this series fix the issue
>> at hand. The first patch is more generic as it will fix it for all drivers,
>> while this patch is specific to the R-Car DU driver. It however makes sense
>> to merge it, as it adds alpha support to the primary plane, which can be
>> useful.
>>
>> Once the first patch gets merged, the above comment won't be correct
>> anymore. I wonder whether we shouldn't change the patch description and
>> comment to focus on usage of the alpha property for primary planes, and not
>> on the bug fix. What's your opinion ?

Aha - sorry this slipped my queue.


> I've removed the comment and changed the commit message to
> 
>   drm: rcar-du: Enable alpha property on primary planes
>   
>   The hardware supports alpha on all planes, and using it on the primary
>   plane can be useful. Don't restrict the alpha property to overlay
>   planes.
> 
> With this,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

Perfect, - That reads fine.

Thank you.



> 
> and applied to my tree.
> 
>>>  		if (type == DRM_PLANE_TYPE_PRIMARY)
>>>  			continue;
>>>  		
>>>  		drm_object_attach_property(&plane->plane.base,
>>>  					   rcdu->props.colorkey,
>>>  					   RCAR_DU_COLORKEY_NONE);
>>>
>>> -		drm_plane_create_alpha_property(&plane->plane);
>>>  		drm_plane_create_zpos_property(&plane->plane, 1, 1, 7);
>>>  	}
>