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Date:   Fri, 13 Sep 2019 10:21:29 +0200
From:   Simon Horman <horms@verge.net.au>
To:     Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc:     Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        linux-renesas-soc@vger.kernel.org,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        "open list:DRM DRIVERS FOR RENESAS" <dri-devel@lists.freedesktop.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drm: rcar-du: Add r8a77980 support
Message-ID: <20190913082129.lvusbp6pbcayqh5r@verge.net.au>
References: <20190911192502.16609-1-kieran.bingham+renesas@ideasonboard.com>
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On Thu, Sep 12, 2019 at 01:00:41PM +0300, Sergei Shtylyov wrote:
> Hello!
> 
> 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.

> > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

> [...]
> 
> MBR, Sergei
>