[PATCH 6/7] drm/vc4: dpi: Change the default DPI format to being 18bpp, not 24.
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Sat Oct 15 17:13:38 UTC 2022
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 at 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 at 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 at raspberrypi.com>
> Signed-off-by: Maxime Ripard <maxime at 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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