Re: [PATCH v13 6/9] dw-hdmi/ingenic-dw-hdmi: repair interworking with hdmi-connector

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Nikolaus,

Le mer., févr. 2 2022 at 17:31:20 +0100, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> a écrit :
Commit 7cd70656d1285b ("drm/bridge: display-connector: implement bus fmts callbacks")

introduced a new mechanism to negotiate bus formats between hdmi connector
and the synopsys hdmi driver inside the jz4780.

By this, the dw-hdmi is no longer the only bridge and sets up a list
of formats in dw_hdmi_bridge_atomic_get_output_bus_fmts().

This includes MEDIA_BUS_FMT_UYVY8_1X16 which is chosen for the jz4780 but only
produces a black screen.

This fix is based on the observation that max_bpc = 0 when running this function while info->bpc = 8. Since the formats checks before this always test for max_bpc >= info->pbc indirectly my assumption is that we must check it
here as well.

This fix looks really strange to me, so I'll let the DRM experts comment.

It would still be better to move the patch before the introduction of dw-ingenic-hdmi.c, so that once this one is introduced, everything works. This also enables bisectability.

Cheers,
-Paul



Adding the proposed patch makes the CI20/jz4780 panel work again in
MEDIA_BUS_FMT_RGB888_1X24 mode.

Fixes: 7cd70656d1285b ("drm/bridge: display-connector: implement bus fmts callbacks")
Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 52e7cd2e020d3..34703a15ee4ff 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -2620,10 +2620,10 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
 		output_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
 	}

-	if (info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
+ if (max_bpc >= info->bpc && info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
 		output_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16;

-	if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
+ if (max_bpc >= info->bpc && info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
 		output_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;

 	/* Default 8bit RGB fallback */
--
2.33.0







[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux