linux-kernel - Re: [PATCH v2 1/5] dt-bindings: display: simple-framebuffer: Add interconnects property

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1555efd6-5a39-4bc7-92d4-63f5c33b1dca@suse.de>
Date: Thu, 3 Jul 2025 10:41:38 +0200
From: Thomas Zimmermann <tzimmermann@...e.de>
To: Hans de Goede <hdegoede@...hat.com>, Krzysztof Kozlowski
 <krzk@...nel.org>, Luca Weiss <luca.weiss@...rphone.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, David Airlie <airlied@...il.com>,
 Simona Vetter <simona@...ll.ch>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Javier Martinez Canillas <javierm@...hat.com>,
 Helge Deller <deller@....de>, linux-fbdev@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/5] dt-bindings: display: simple-framebuffer: Add
 interconnects property

Hi

Am 03.07.25 um 10:34 schrieb Hans de Goede:
> Hi Thomas,
>
> On 3-Jul-25 8:47 AM, Thomas Zimmermann wrote:
>> Hi
>>
>> Am 02.07.25 um 22:43 schrieb Krzysztof Kozlowski:
>>> On 30/06/2025 10:40, Hans de Goede wrote:
>>>>> No one asks to drop them from the driver. I only want specific front
>>>>> compatible which will list and constrain the properties. It is not
>>>>> contradictory to your statements, U-boot support, driver support. I
>>>>> really do not see ANY argument why this cannot follow standard DT rules.
>>>> So what you are saying is that you want something like:
>>>>
>>>> framebuffer0: framebuffer@...85000 {
>>>>      compatible = "qcom.simple-framebuffer-sm8650-mdss", "simple-framebuffer";
>>>> }
>>>>
>>>> and that the binding for qcom.simple-framebuffer-sm8650-mdss
>>>> can then list interconnects ?
>>> IMO yes (after adjusting above to coding style), but as mentioned in
>>> other response you can just get an ack or opinion from Rob or Conor.
>> But does that work with *any* device that requires interconnects? The next such simple-framebuffer device should work out of the box *without* the kernel knowing anything about it. That's one of the key features of the simple-framebuffer.  If we have to maintainer per-device feature sets, it breaks that assumption.
> The driver code for this can still be generic and since the driver
> will bind to the fallback plain "simple-framebuffer" compatible
> this should also work for new platforms.
>
> The e.g. "qcom.simple-framebuffer-sm8650-mdss" compatible would
> purely be something in the dt-bindings to document which simplefb
> implementations will have interconnects and which ones will not.
>
> The driver does not necessarily need to check these more
> precise compatibles, it can still just check for the generic
> presence of interconnects.

Thanks, that's good to hear.

Best regards
Thomas

>
> Regards,
>
> Hans
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)