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References: <20230515235713.232939-1-aford173@gmail.com> <20230515235713.232939-7-aford173@gmail.com>
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From:   Jagan Teki <jagan@amarulasolutions.com>
Date:   Thu, 18 May 2023 17:37:09 +0530
Message-ID: <CAMty3ZBqdE8mLiwFa=QRChBYyQnsOEMYqh2Azj4TxbZbErCsBA@mail.gmail.com>
Subject: Re: [PATCH V6 6/6] drm: bridge: samsung-dsim: Support non-burst mode
To:     Adam Ford <aford173@gmail.com>
Cc:     dri-devel@lists.freedesktop.org, aford@beaconembedded.com,
        Chen-Yu Tsai <wenst@chromium.org>,
        Frieder Schrempf <frieder.schrempf@kontron.de>,
        Andrzej Hajda <andrzej.hajda@intel.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Robert Foss <rfoss@kernel.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Inki Dae <inki.dae@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Marek Vasut <marex@denx.de>, linux-kernel@vger.kernel.org
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On Tue, May 16, 2023 at 5:27=E2=80=AFAM Adam Ford <aford173@gmail.com> wrot=
e:
>
> The high-speed clock is hard-coded to the burst-clock
> frequency specified in the device tree.  However, when
> using devices like certain bridge chips without burst mode
> and varying resolutions and refresh rates, it may be
> necessary to set the high-speed clock dynamically based
> on the desired pixel clock for the connected device.
>
> This also removes the need to set a clock speed from
> the device tree for non-burst mode operation, since the
> pixel clock rate is the rate requested from the attached
> device like a bridge chip.  This should have no impact
> for people using burst-mode and setting the burst clock
> rate is still required for those users.  If the burst
> clock is not present, change the error message to
> dev_info indicating the clock use the pixel clock.
>
> Signed-off-by: Adam Ford <aford173@gmail.com>
> Tested-by: Chen-Yu Tsai <wenst@chromium.org>
> Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  drivers/gpu/drm/bridge/samsung-dsim.c | 27 +++++++++++++++++++++------
>  1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/brid=
ge/samsung-dsim.c
> index 3944b7cfbbdf..03b21d13f067 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -655,16 +655,28 @@ static unsigned long samsung_dsim_set_pll(struct sa=
msung_dsim *dsi,
>
>         dsi->hs_clock =3D fout;
>
> +       dsi->hs_clock =3D fout;

I dropped this and tested it.

Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> # imx8mm-icore