On 08/04/2022 12:32, Sandor Yu wrote:
HDMI1.4b specification section 6.5.3: Source shall only send GCPs with non-zero CD to sinks that indicate support for Deep Color.
DW HDMI GCP default enabled, clear gpc_auto bit for 24-bit color depth.
It's right because we do not handle AVMUTE, Pixel Packing nor Default_Phase.
Signed-off-by: Sandor Yu Sandor.yu@nxp.com
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c index 02d8f7e08814..5a7ec066e37a 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c @@ -1108,6 +1108,8 @@ static void hdmi_video_packetize(struct dw_hdmi *hdmi) unsigned int output_select = HDMI_VP_CONF_OUTPUT_SELECTOR_PP; struct hdmi_data_info *hdmi_data = &hdmi->hdmi_data; u8 val, vp_conf;
u8 clear_gcp_auto = 0;
if (hdmi_bus_fmt_is_rgb(hdmi->hdmi_data.enc_out_bus_format) || hdmi_bus_fmt_is_yuv444(hdmi->hdmi_data.enc_out_bus_format) ||
@@ -1117,6 +1119,7 @@ static void hdmi_video_packetize(struct dw_hdmi *hdmi) case 8: color_depth = 4; output_select = HDMI_VP_CONF_OUTPUT_SELECTOR_BYPASS;
clear_gcp_auto = 1; break;@@ -1136,6 +1139,7 @@ static void hdmi_video_packetize(struct dw_hdmi *hdmi) case 0: case 8: remap_size = HDMI_VP_REMAP_YCC422_16bit;
clear_gcp_auto = 1; break;@@ -1160,6 +1164,14 @@ static void hdmi_video_packetize(struct dw_hdmi *hdmi) HDMI_VP_PR_CD_DESIRED_PR_FACTOR_MASK); hdmi_writeb(hdmi, val, HDMI_VP_PR_CD);
- val = hdmi_readb(hdmi, HDMI_FC_DATAUTO3);
- if (clear_gcp_auto == 1)
/* disable Auto GCP when 24-bit color */
Maybe add a new define for HDMI_FC_DATAUTO3_GCP_AUTO bit and use it here.
val &= ~0x4;- else
val |= 0x4;- hdmi_writeb(hdmi, val, HDMI_FC_DATAUTO3);
Please also add a comment explaining we clear GCP because we only transmit CD and do not handle AVMUTE, PP nor Default_Phase (yet).
- hdmi_modb(hdmi, HDMI_VP_STUFF_PR_STUFFING_STUFFING_MODE, HDMI_VP_STUFF_PR_STUFFING_MASK, HDMI_VP_STUFF);
Thanks, Neil