Hi Laurent, Jacopo,
On Wed, Jun 19, 2024 at 9:46 PM Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> On Wed, Jun 19, 2024 at 12:22:18PM +0200, Jacopo Mondi wrote:
> > Add support for R-Car R8A779H0 V4M which has similar characteristics
> > as the already supported R-Car V4H R8A779G0, but with a single output
> > channel.
> >
> > Signed-off-by: Jacopo Mondi <jacopo.mondi@xxxxxxxxxxxxxxxx>
> > --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c
> > +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c
> > @@ -185,11 +187,16 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
> > dorcr |= DORCR_PG1T | DORCR_DK1S | DORCR_PG1D_DS1;
> > rcar_du_group_write(rgrp, DORCR, dorcr);
> >
> > - /* Apply planes to CRTCs association. */
> > - mutex_lock(&rgrp->lock);
> > - rcar_du_group_write(rgrp, DPTSR, (rgrp->dptsr_planes << 16) |
> > - rgrp->dptsr_planes);
> > - mutex_unlock(&rgrp->lock);
> > + /*
> > + * Apply planes to CRTCs association, skip for V4M which has a single
> > + * channel.
>
> " and doesn't implement the DPTSR register."
>
> I'm pretty sure writing it is still harmless, but...
>
> > + */
> > + if (rcdu->info->gen < 4 || rgrp->num_crtcs > 1) {
Looking at the R-Car Gen3 docs, this check seems to be wrong, and the
lack of a check might have been an issue before?
Seems like the register (per pair) is only present if the second CRTC
of a CRTC pair is present, so R-Car V3M and V3H (single CRTC) do not
have DPTSR at all, and M3-W (triple CRTC) does not have it on the
second pair. M3-N does have both, as it lacks the first CRTC of
second pair, but does have the second CRTC of the second pair.
> > + mutex_lock(&rgrp->lock);
> > + rcar_du_group_write(rgrp, DPTSR, (rgrp->dptsr_planes << 16) |
> > + rgrp->dptsr_planes);
> > + mutex_unlock(&rgrp->lock);
> > + }
> > }
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
