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    SubjectRe: [PATCH 5.17 404/772] media: rkvdec: Stop overclocking the decoder
    Hi,

    On Tue, Jun 07, 2022 at 06:59:56PM +0200, Greg Kroah-Hartman wrote:
    > From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
    >
    > [ Upstream commit 9998943f6dfc5d5472bfab2e38527fb6ba5e9da7 ]
    >
    > While this overclock hack seems to work on some implementations
    > (some ChromeBooks, RockPi4) it also causes instability on other
    > implementations (notably LibreComputer Renegade, but there were more
    > reports in the LibreELEC project, where this has been removed). While
    > performance is indeed affected (tested with GStreamer), 4K playback
    > still works as long as you don't operate in lock step and keep at
    > least 1 frame ahead of time in the decode queue.
    >
    > After discussion with ChromeOS members, it would seem that their
    > implementation indeed used to synchronously decode each frame, so
    > this hack was simply compensating for their code being less
    > efficient. In my opinion, this hack should not have been included
    > upstream.
    >
    > Fixes: cd33c830448ba ("media: rkvdec: Add the rkvdec driver")
    > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
    > Reviewed-by: Sebastian Fricke <sebastian.fricke@collabora.com>
    > Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
    > Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
    > Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
    > Signed-off-by: Sasha Levin <sashal@kernel.org>

    FWIW, I've noticed a problem that is uncovered by this patch, because
    the default clock rate is not currently acceptable all the time. See my
    fix here:

    https://lore.kernel.org/all/20220607141535.1.Idafe043ffc94756a69426ec68872db0645c5d6e2@changeid/
    [PATCH] arm64: dts: rockchip: Assign RK3399 VDU clock rate

    It might be nice if $subject patch could be delayed until the fix is in
    too. The 5.19 cycle is only in -rc1, after all.

    (The same seems to apply for the 5.{18,15,10}.y series too.)

    Brian

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