linux-kernel - Re: [PATCH v2] drm: bridge: fsl-ldb: fixup mode on freq mismatch

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: <bb14f0aca5d14141b45700abf10deb61@vosn.de>
Date: Sat, 07 Dec 2024 07:30:27 +0100
From: Nikolaus Voss <nv@...n.de>
To: Miquel Raynal <miquel.raynal@...tlin.com>
Cc: Alexander Stein <alexander.stein@...tq-group.com>, Liu Ying
 <victor.liu@....com>, Luca Ceresoli <luca.ceresoli@...tlin.com>, Fabio
 Estevam <festevam@...x.de>, Marek Vasut <marex@...x.de>, Andrzej Hajda
 <andrzej.hajda@...el.com>, Neil Armstrong <neil.armstrong@...aro.org>,
 Robert Foss <rfoss@...nel.org>, Laurent Pinchart
 <Laurent.pinchart@...asonboard.com>, Jonas Karlman <jonas@...boo.se>, Jernej
 Skrabec <jernej.skrabec@...il.com>, David Airlie <airlied@...il.com>, Daniel
 Vetter <daniel@...ll.ch>, nikolaus.voss@...g-streit.com,
 dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] drm: bridge: fsl-ldb: fixup mode on freq mismatch

Hi Miquèl,

On 06.12.2024 15:08, Miquel Raynal wrote:
> On 03/12/2024 at 20:09:52 +01, Nikolaus Voss <nv@...n.de> wrote:
> 
>> LDB clock has to be a fixed multiple of the pixel clock.
> 
> Not only, IIUC it also needs to be synchronized, ie. share the same
> source.
> 
>> As LDB and pixel clock are derived from different clock sources
>> (at least on imx8mp),
> 
> Wait, what? I am sorry but that is not at all recommended, both should
> come from video_pll1 which the de-facto versatile PLL to use, no? Am I
> missing something here?

No, I was wrong :-). I've corrected the log text in the v3.

-- 
Nikolaus Voss