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

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Message-ID: <CAG3jFyt802J8nxtc_iifgfbTJk0-Mtu_18aY0cEcjyJDaNLjaA@mail.gmail.com>
Date:   Tue, 30 Nov 2021 13:17:28 +0100
From:   Robert Foss <robert.foss@...aro.org>
To:     Vinod Koul <vkoul@...nel.org>
Cc:     Peter Collingbourne <pcc@...gle.com>,
        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 Tue, 30 Nov 2021 at 06:30, Vinod Koul <vkoul@...nel.org> wrote:
>
> 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>
>

Applied to drm-misc-next