Re: [PATCH 3/5] drm/rcar-du: dsc: Add rudimentary Renesas R-Car V4H DSC driver

[Geert Uytterhoeven]

Hi Tomi,

On Thu, 14 May 2026 at 14:25, Tomi Valkeinen
<tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx> wrote:
> From: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
>
> The Renesas DSC Display Stream Compression is a bridge embedded in the
> Renesas R-Car V4H SoC. The bridge performs VESA DSC encoding of up to
> 8k or 400 Mpixel/s . Add rudimentary driver, which currently acts as a
> pass-through bridge and allows DSI1 to be operational on R-Car V4H.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx>
> [tomi.valkeinen: use bridge->next_bridge, minor changes]
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>

Thanks for your patch!

> --- /dev/null
> +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_dsc.c

> +
> +static void rcar_dsc_atomic_enable(struct drm_bridge *bridge,
> +                                  struct drm_atomic_state *state)
> +{
> +       struct rcar_dsc *dsc = bridge_to_rcar_dsc(bridge);
> +
> +       WARN_ON(clk_prepare_enable(dsc->clk));

Who don't you use pm_runtime_resume_and_get() instead, like
rcar_cmm.c? Then you don't need to get the clock at all, and the driver
will keep on working if the DSC ever ends up in a power domain.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds