Hi Tomi,
On Fri, 15 May 2026 at 10:03, Tomi Valkeinen
<[email protected]> wrote:
> On 15/05/2026 10:49, Geert Uytterhoeven wrote:
> > On Thu, 14 May 2026 at 14:25, Tomi Valkeinen
> > <[email protected]> wrote:
> >> From: Marek Vasut <[email protected]>
> >>
> >> 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 <[email protected]>
> >> [tomi.valkeinen: use bridge->next_bridge, minor changes]
> >> Signed-off-by: Tomi Valkeinen <[email protected]>
> >
> > 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));
>
> Ah, just missed your comment and sent the v2.
>
> > 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
>
> Hmm, why wouldn't I need to get the clock? What does the runtime PM do
> on Renesas?
Runtime PM powers on the power domain (if present), and starts
the device by enabling its module clock.
> > will keep on working if the DSC ever ends up in a power domain.
> I can add runtime PM. I just felt that it was overcomplicating a "dummy"
> driver that just needs to enable the clock when the video pipeline is
> enabled.
Funny, I would say you are overcomplicating a dummy driver by adding
explicit clock control ;-)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
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
