On 06/04/2022 10:48, Sandor.yu@xxxxxxx wrote:
From: Sandor Yu <Sandor.yu@xxxxxxx>
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 GPC default enabled, clear gpc_auto bit for bpp 24.
Signed-off-by: Sandor Yu <Sandor.yu@xxxxxxx>
---
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index b11577de4836..c7b11582529e 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -1160,6 +1160,14 @@ 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 (color_depth == 4)
+ /* disable Auto GCP when bpp 24 */
+ val &= ~0x4;
+ else
+ val |= 0x4;
+ hdmi_writeb(hdmi, val, HDMI_FC_DATAUTO3);
+
hdmi_modb(hdmi, HDMI_VP_STUFF_PR_STUFFING_STUFFING_MODE,
HDMI_VP_STUFF_PR_STUFFING_MASK, HDMI_VP_STUFF);
Do you handle the case when color_depth == 0 when output is YUV422 ?
Neil
