Re: [PATCH] drm: rcar-du: Add r8a77980 support
From: Laurent Pinchart
Date: Thu Dec 12 2019 - 19:48:28 EST
On Mon, Dec 09, 2019 at 12:41:07PM +0000, Kieran Bingham wrote:
> On 13/09/2019 10:03, Laurent Pinchart wrote:
> > 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>
> 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?
Could you just confirm I should apply this patch, and not go for the
alternative proposal above ?
> >>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> >> Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>