Re: [PATCH] drm: rcar-du: Add r8a77980 support

From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	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
Date: Thu, 12 Sep 2019 13:11:37 +0100	[thread overview]
Message-ID: <b0b689e6-2f99-049f-23a7-213678d6a7a6@ideasonboard.com> (raw)
In-Reply-To: <CAMuHMdVYqx_znkMbwCVyA6WH8-0uOotL3wXCTkvyXG1=i9W-ng@mail.gmail.com>

On 12/09/2019 13:03, Geert Uytterhoeven wrote:
> Hi Kieran,
> 
> On Thu, Sep 12, 2019 at 12:26 PM Kieran Bingham
> <kieran.bingham+renesas@ideasonboard.com> wrote:
>> (pulling in +Geert for his opinion on compatible string usages)
>>
>> On 12/09/2019 11:00, 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.
>>
>> It's not just about the compatible string for me here,
>>
>> There is no indication in the driver that it supports the r8a77980, and
>> no comment in the driver to explain that the r8a77980 is shared by the
>> r8a77970.
>>
>> This patch makes that explicit at the driver.
>>
>> Also - I am considering sending a patch (that I've already created
>> anyway) to remove the r8a77970 reference from the
>>
>>   arch/arm64/boot/dts/renesas/r8a77980.dtsi file.
>>
>> This is the *only* non r8a77980 reference in this file, so it seems very
>> out of place.
> 
> Agreed.
> 
>> In fact more so than that - except for a seemingly glaring typo, that
>> I'll investigate and send a patch for next, this is the *only* cross-soc
>> compatible reference:
>>
>> #!/bin/sh
>>
>> files=r8a77*.dtsi
>>
>> for f in $files;
>> do
>>         soc=`basename $f .dtsi | sed 's/-.*//'`
>>         echo "F: $f soc: $soc";
>>
>>         # Find all references to all socs, then hide 'this' soc
>>         grep r8a77 $f | grep -v $soc
> 
> This hides the complete line.  So you better use e.g.
> 
>     sed -e "s/$soc/soc/ig" $f | grep -i r8a

Aha yes, excellent point! (I'm glad I posted my working)

> 
> instead.  No new offenders, though.

Phew, I still got the right answer :-D

--
Kieran