2022-01-21 19:13:57

by Neil Armstrong

Subject: [PATCH 1/2] drm/bridge: dw-hdmi: filter safe formats when first in bridge chain

If the dw-bridge is in the first position in the bridge chain, this
means there is no way to set the encoder output bus format.

In this case, this makes sure we only return the default format as return
of the get_input_bus_fmts() callback, limiting possible output formats
of dw-hdmi to what the dw-hdmi can convert from the default RGB24 input
format.

Fixes: 6c3c719936da ("drm/bridge: synopsys: dw-hdmi: add bus format negociation")
Signed-off-by: Neil Armstrong <[email protected]>
---
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 97cdc61b57f6..56021f20d396 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -2674,6 +2674,25 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
if (!input_fmts)
return NULL;

+ /* If dw-hdmi is the first bridge make sure it only takes RGB24 as input */
+ if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain)) {
+ switch (output_fmt) {
+ case MEDIA_BUS_FMT_FIXED:
+ case MEDIA_BUS_FMT_RGB888_1X24:
+ case MEDIA_BUS_FMT_YUV8_1X24:
+ case MEDIA_BUS_FMT_UYVY8_1X16:
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
+ break;
+ default:
+ kfree(input_fmts);
+ input_fmts = NULL;
+ }
+
+ *num_input_fmts = i;
+
+ return input_fmts;
+ }
+
switch (output_fmt) {
/* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */
case MEDIA_BUS_FMT_FIXED:
--
2.25.1

2022-01-21 19:13:58

by Neil Armstrong

Subject: [PATCH 2/2] drm/bridge: dw-hdmi: filter out YUV output formats when DVI

When the display is not an HDMI sink, only the RGB output format is
valid. Thus stop returning YUV output formats when sink is not HDMI.

Fixes: 6c3c719936da ("drm/bridge: synopsys: dw-hdmi: add bus format negociation")
Signed-off-by: Neil Armstrong <[email protected]>
---
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 56021f20d396..03057d335158 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -2538,6 +2538,7 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
struct drm_connector *conn = conn_state->connector;
struct drm_display_info *info = &conn->display_info;
struct drm_display_mode *mode = &crtc_state->mode;
+ struct dw_hdmi *hdmi = bridge->driver_private;
u8 max_bpc = conn_state->max_requested_bpc;
bool is_hdmi2_sink = info->hdmi.scdc.supported ||
(info->color_formats & DRM_COLOR_FORMAT_YCRCB420);
@@ -2564,7 +2565,7 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
* If the current mode enforces 4:2:0, force the output but format
* to 4:2:0 and do not add the YUV422/444/RGB formats
*/
- if (conn->ycbcr_420_allowed &&
+ if (hdmi->sink_is_hdmi && conn->ycbcr_420_allowed &&
(drm_mode_is_420_only(info, mode) ||
(is_hdmi2_sink && drm_mode_is_420_also(info, mode)))) {

@@ -2595,36 +2596,36 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
*/

if (max_bpc >= 16 && info->bpc == 16) {
- if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
+ if (hdmi->sink_is_hdmi && info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
output_fmts[i++] = MEDIA_BUS_FMT_YUV16_1X48;

output_fmts[i++] = MEDIA_BUS_FMT_RGB161616_1X48;
}

if (max_bpc >= 12 && info->bpc >= 12) {
- if (info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
+ if (hdmi->sink_is_hdmi && info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
output_fmts[i++] = MEDIA_BUS_FMT_UYVY12_1X24;

- if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
+ if (hdmi->sink_is_hdmi && info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
output_fmts[i++] = MEDIA_BUS_FMT_YUV12_1X36;

output_fmts[i++] = MEDIA_BUS_FMT_RGB121212_1X36;
}

if (max_bpc >= 10 && info->bpc >= 10) {
- if (info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
+ if (hdmi->sink_is_hdmi && info->color_formats & DRM_COLOR_FORMAT_YCRCB422)
output_fmts[i++] = MEDIA_BUS_FMT_UYVY10_1X20;

- if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
+ if (hdmi->sink_is_hdmi && info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
output_fmts[i++] = MEDIA_BUS_FMT_YUV10_1X30;

output_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
}

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

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

/* Default 8bit RGB fallback */
--
2.25.1