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From:   Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date:   Thu, 18 Aug 2022 21:36:35 +0100
Message-ID: <CADVatmOKemXQbRpJeeqR2NbWMkUc9U09xrch=OpDkxFXqbH8XA@mail.gmail.com>
Subject: Re: drm warning with mainline due to 467e30171b5b ("drm/vc4: hdmi:
 Move HDMI reset to pm_resume")
To:     Maxime Ripard <maxime@cerno.tech>
Cc:     Dave Stevenson <dave.stevenson@raspberrypi.com>,
        Emma Anholt <emma@anholt.net>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
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On Wed, Aug 17, 2022 at 8:10 AM Maxime Ripard <maxime@cerno.tech> wrote:
>
> Hi,
>
> On Tue, Aug 16, 2022 at 05:34:51PM +0100, Sudip Mukherjee (Codethink) wrote:
> > Not sure if it has been reported but the mainline kernel shows a drm warning
> > on RPI4B.
> >
> > [   14.821276] WARNING: CPU: 3 PID: 187 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:487 vc5_hdmi_reset+0x1f8/0x240 [vc4]

<snip>

> >
> > git bisect pointed to 467e30171b5b ("drm/vc4: hdmi: Move HDMI reset to pm_resume")
> > and reverting this commit has fixed the warning.
> >
> > I will be happy to test any patch or provide any extra log if needed.
>
> We have fixes for this in drm-misc-next that have missed the cut for the
> merge window:
>
> https://lore.kernel.org/all/20220629123510.1915022-38-maxime@cerno.tech/
> https://lore.kernel.org/all/20220629123510.1915022-39-maxime@cerno.tech/
>
> If it fixes it for you, I'll apply it to drm-misc-fixes

Thanks. With these two patches applied on top of the latest mainline,
I don't see the warning anymore.

Tested-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>


-- 
Regards
Sudip