linux-kernel - Re: [PATCH] lontium-lt9611: check a different register bit for HDMI sensing

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: <YaW3Cff+AJqT8tS/@matsya>
Date:   Tue, 30 Nov 2021 11:00:49 +0530
From:   Vinod Koul <vkoul@...nel.org>
To:     Peter Collingbourne <pcc@...gle.com>
Cc:     Robert Foss <robert.foss@...aro.org>,
        John Stultz <john.stultz@...aro.org>,
        Anibal Limon <anibal.limon@...aro.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] lontium-lt9611: check a different register bit for HDMI
 sensing

On 16-11-21, 18:07, Peter Collingbourne wrote:
> It has been observed that with certain monitors such as the HP Z27n,
> the register 0x825e reads a value of 0x79 when the HDMI cable is
> connected and 0x78 when it is disconnected, i.e. bit 0 appears
> to correspond to the HDMI connection status and bit 2 is never
> set. Therefore, change the driver to check bit 0 instead of bit 2.

So we have got limited information on this but BIT-2 seems to be related
to HPD and empirical data from various monitors supports this, so this
seems the right thing to do.

Reviewed-by: Vinod Koul <vkoul@...nel.org>

-- 
~Vinod