Re: [PATCH] drm: rcar-du: Add r8a77980 support
From: Kieran Bingham
Date: Mon Dec 09 2019 - 07:41:16 EST
Hi Laurent,
On 13/09/2019 10:03, Laurent Pinchart wrote:
> Hello,
>
> On Fri, Sep 13, 2019 at 10:21:29AM +0200, Simon Horman wrote:
>> On Thu, Sep 12, 2019 at 01:00:41PM +0300, Sergei Shtylyov wrote:
>>> On 11.09.2019 22:25, Kieran Bingham wrote:
>>>
>>>> Add direct support for the r8a77980 (V3H).
>>>>
>>>> The V3H shares a common, compatible configuration with the r8a77970
>>>> (V3M) so that device info structure is reused.
>>>
>>> Do we really need to add yet another compatible in this case?
>>> I just added r8a77970 to the compatible prop in the r8a77980 DT. That's why
>>> a patch like this one didn't get posted by me.
>>
>> The reason for having per-SoC compat strings is that the IP blocks
>> are not versioned and while we can observe that there are similarities
>> between, f.e. the DU on the r8a77970 and r8a77980, we can't be certain that
>> differences may not emerge at some point. By having per-SoC compat strings
>> we have the flexibility for the driver to address any such differences as
>> the need arises.
>>
>> My recollection is that this scheme has been adopted for non-versioned
>> Renesas IP blocks since June 2015 and uses of this scheme well before that.
>
> Sure, but we could use
>
> compatible = "renesas,du-r8a77980", "renesas,du-r8a77970";
>
> in DT without updating the driver. If the r8a77980 turns out to be
> different, we'll then update the driver without a need to modify DT. I'm
> fine either way, so
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Thanks,
This patch has an RB tag from you, and Simon, but alas I don't believe
it has been picked up in your drm/du/next branch.
Is this patch acceptable? Or do I need to repost?
--
Kieran
>
>>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>>
>> Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
>