From 052b9cfb8f4c04fd6f19f52752929e0f9cc55552 Mon Sep 17 00:00:00 2001
From: Fangzhi Zuo <Jerry.Zuo@amd.com>
Date: Tue, 30 Aug 2022 12:12:53 -0400
Subject: drm/amd/display: Validate DSC After Enable All New CRTCs
Git-commit: 876fcc4222e1d0e5b73343f4010a8b66be058f48
Patch-mainline: v6.1-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849

Before enabling new crtc, stream_count in dc_state does not sync with
that in drm_atomic_state. Validating dsc in such case would leave newly
added stream not jointly participating in dsc optimization with existing
streams, but simply using default initialized vcpi all the time which
gives wrong dsc determination decision.

Consider the scenaio where one 4k60 connected to the dock under dp-alt mode.
Since dp-alt mode is 2-lane setup, stream 1 consumes 63 slots with dsc needed.
Then hook up a second 4k60 to the dock.
stream 2 connected with 65 slot initialized by default without dsc.  dsc
pre validate will not jointly optimize stream 2 with stream 1 before
crtc 2 added into the dc_state. That leads to stream 2 not getting dsc
optimization, and trigger atomic_check failure all the time, as 65 > 63
limit.

After getting all new crtcs added into the state, stream_count in
dc_state correctly reflect that in drm_atomic_state which comes up with
correct dsc decision.

Fixes: 71be4b16d39a ("drm/amd/display: dsc validate fail not pass to atomic check")
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 46c8abbb36bb..59213975b46c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9373,10 +9373,6 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 				}
 			}
 		}
-		if (!pre_validate_dsc(state, &dm_state, vars)) {
-			ret = -EINVAL;
-			goto fail;
-		}
 	}
 #endif
 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
@@ -9510,6 +9506,15 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 		}
 	}
 
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+	if (dc_resource_is_dsc_encoding_supported(dc)) {
+		if (!pre_validate_dsc(state, &dm_state, vars)) {
+			ret = -EINVAL;
+			goto fail;
+		}
+	}
+#endif
+
 	/* Run this here since we want to validate the streams we created */
 	ret = drm_atomic_helper_check_planes(dev, state);
 	if (ret) {
-- 
2.38.1