Messages in this thread | | | Date | Sat, 15 Oct 2022 20:13:38 +0300 | From | Laurent Pinchart <> | Subject | Re: [PATCH 6/7] drm/vc4: dpi: Change the default DPI format to being 18bpp, not 24. |
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Hi Maxime (and Dave),
Thank you for the patch.
On Thu, Oct 13, 2022 at 11:56:50AM +0200, Maxime Ripard wrote: > From: Dave Stevenson <dave.stevenson@raspberrypi.com> > > DPI hasn't really been used up until now, so the default has > been meaningless. > In theory we should be able to pass the desired format for the > adjacent bridge chip through, but framework seems to be missing > for that.
Doesn't the bridge infrastructure allow that ? Or maybe this commit message was written a while ago, before it was possible ?
In any case, it would be nice to use the bus format exposed by the next bridge in the chain, but that can be done in a subsequent step. The new default seems reasonable.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> As the main device to use DPI is the VGA666 or Adafruit Kippah, > both of which use RGB666, change the default to being RGB666 instead > of RGB888. > > Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> > Signed-off-by: Maxime Ripard <maxime@cerno.tech> > --- > drivers/gpu/drm/vc4/vc4_dpi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c > index ecbe4cd87036..fdae02760b6d 100644 > --- a/drivers/gpu/drm/vc4/vc4_dpi.c > +++ b/drivers/gpu/drm/vc4/vc4_dpi.c > @@ -150,8 +150,8 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder) > } > drm_connector_list_iter_end(&conn_iter); > > - /* Default to 24bit if no connector or format found. */ > - dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT); > + /* Default to 18bit if no connector or format found. */ > + dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1, DPI_FORMAT); > > if (connector) { > if (connector->display_info.num_bus_formats) { >
-- Regards,
Laurent Pinchart
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