linux-kernel - Re: [PATCH v3] drm: of: Properly try all possible cases for bridge/panel detection

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: <Yl6HYke4dJsrq9jj@aptenodytes>
Date:   Tue, 19 Apr 2022 11:56:50 +0200
From:   Paul Kocialkowski <paul.kocialkowski@...tlin.com>
To:     Paul Cercueil <paul@...pouillou.net>
Cc:     airlied@...ux.ie, daniel@...ll.ch, dri-devel@...ts.freedesktop.org,
        jagan@...rulasolutions.com, linus.walleij@...aro.org,
        linux-kernel@...r.kernel.org, maarten.lankhorst@...ux.intel.com,
        mripard@...nel.org, thomas.petazzoni@...tlin.com,
        tzimmermann@...e.de
Subject: Re: [PATCH v3] drm: of: Properly try all possible cases for
 bridge/panel detection

Hi Paul,

On Sat 16 Apr 22, 23:21, Paul Cercueil wrote:
> Hi Paul,
> 
> This patch breaks the ingenic-drm driver.
> 
> It calls drm_of_find_panel_or_bridge(np, 0, i, ...) starting for i=0, until
> -ENODEV is returned, which does not happen anymore.
> 
> The idea is to probe all the connected panels/bridges, should it be done
> differently now?

I've sent out a different patch which restores -ENODEV at:
https://patchwork.freedesktop.org/patch/481135/

Feel free to try it and reply with tested-by/reviewed-by there.
I've also made a proposal in the thread to skip the "child node" mechanism
as soon as an of graph is present, which would allow covering more legit
cases with -ENODEV (the patch linked above doesn't cover all cases that
need -ENODEV).

Ideally we'd like to remove the child node mechanism entirely, but it may
already be part of a device-tree binding spec.

Cheers,

Paul

-- 
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)