[PATCH 24/74] drm/amd/display: Enable SST PCON FRL DSC passthrough

[Wayne Lin <Wayne.Lin@amd.com>]

From: Fangzhi Zuo <jerry.zuo@amd.com>

[Why]
The SST DSC passthrough to FRL endpoint is not activated yet,
that leads to an FRL sink received DSC_DECODING
instead of DSC_PASSTHROUGH even when the stream selected FRL DSC.

[How]
Make the SST PCON path unconditional and select DSC_PASSTHROUGH when
DSC is enabled for an FRL stream. Preserve the existing default
DSC_DECODING and DSC_DISABLE values for non-FRL enable and disable
operations.

Cc: Ivan Lipski <ivan.lipski@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c    | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 3067ac5bb0cd..6192c0f6086d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -1022,10 +1022,15 @@ bool dm_helpers_dp_write_dsc_enable(
 				   "SST_DSC Send DSC %s to SST RX\n",
 				   enable_dsc ? "enable" : "disable");
 		} else if (stream->sink->link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_HDMI_CONVERTER) {
+			if (enable && stream->timing.dsc_cfg.is_frl)
+				enable_dsc = DSC_PASSTHROUGH;
+
 			ret = dm_helpers_dp_write_dpcd(ctx, stream->link, DP_DSC_ENABLE, &enable_dsc, 1);
 			drm_dbg_dp(dev,
-				   "SST_DSC Send DSC %s to DP-HDMI PCON\n",
-				   enable_dsc ? "enable" : "disable");
+				   "SST_DSC Send DSC %s to %s\n",
+				   enable_dsc ? "enable" : "disable",
+				   stream->timing.dsc_cfg.is_frl ? "HDMI FRL RX" :
+				   "DP-HDMI PCON");
 		}
 	}
 
-- 
2.43.0