From: "Jerry (Fangzhi) Zuo" <Jerry.Zuo@amd.com>
Date: Fri, 22 Jun 2018 17:12:47 -0400
Subject: drm/amd/display: Add YCbCr420 only support for HDMI 4K@60
Git-commit: e7baae1cfb7fd1a31fa8c968403cbc761cf999ff
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
[Why]
Some monitors mark 4K@60 capable HDMI port only have 300MHz TMDS
maximum, but the edid includes 4K@60 mode in cea extension block.
[How]
To enable 4K@60, need to limit BW by allowing YCbCr420 ONLY mode.
Add YCbCr420 only support for monitors that do not fully support
HDMI2.0, e.g., ASUS PA328. The YCbCr420 only support applies to
DCN, DCE112 or higher.
Signed-off-by: Jerry (Fangzhi) Zuo <Jerry.Zuo@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3509,7 +3509,6 @@ void amdgpu_dm_connector_init_helper(str
aconnector->base.stereo_allowed = false;
aconnector->base.dpms = DRM_MODE_DPMS_OFF;
aconnector->hpd.hpd = AMDGPU_HPD_NONE; /* not used */
-
mutex_init(&aconnector->hpd_lock);
/* configure support HPD hot plug connector_>polled default value is 0
@@ -3518,9 +3517,13 @@ void amdgpu_dm_connector_init_helper(str
switch (connector_type) {
case DRM_MODE_CONNECTOR_HDMIA:
aconnector->base.polled = DRM_CONNECTOR_POLL_HPD;
+ aconnector->base.ycbcr_420_allowed =
+ link->link_enc->features.ycbcr420_supported ? true : false;
break;
case DRM_MODE_CONNECTOR_DisplayPort:
aconnector->base.polled = DRM_CONNECTOR_POLL_HPD;
+ aconnector->base.ycbcr_420_allowed =
+ link->link_enc->features.ycbcr420_supported ? true : false;
break;
case DRM_MODE_CONNECTOR_DVID:
aconnector->base.polled = DRM_CONNECTOR_POLL_HPD;