[PATCH 22/25] drm/amd/display: Fix hang/underflow when transitioning to ODM4:1

[Wayne Lin]

From: Ilya Bakoulin <ilya.bakoulin at amd.com>

[Why]
Under some circumstances, disabling an OPTC and attempting to reclaim
its OPP(s) for a different OPTC could cause a hang/underflow due to OPPs
not being properly disconnected from the disabled OPTC.

[How]
Ensure that all OPPs are unassigned from an OPTC when it gets disabled.

Reviewed-by: Alvin Lee <alvin.lee2 at amd.com>
Acked-by: Wayne Lin <wayne.lin at amd.com>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin at amd.com>
---
 drivers/gpu/drm/amd/display/dc/optc/dcn32/dcn32_optc.c | 7 +++++++
 drivers/gpu/drm/amd/display/dc/optc/dcn35/dcn35_optc.c | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/optc/dcn32/dcn32_optc.c b/drivers/gpu/drm/amd/display/dc/optc/dcn32/dcn32_optc.c
index a2c4db2cebdd..91ea0d4da06a 100644
--- a/drivers/gpu/drm/amd/display/dc/optc/dcn32/dcn32_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/optc/dcn32/dcn32_optc.c
@@ -172,6 +172,13 @@ static bool optc32_disable_crtc(struct timing_generator *optc)
 	REG_UPDATE(OTG_CONTROL,
 			OTG_MASTER_EN, 0);
 
+	REG_UPDATE_5(OPTC_DATA_SOURCE_SELECT,
+			OPTC_SEG0_SRC_SEL, 0xf,
+			OPTC_SEG1_SRC_SEL, 0xf,
+			OPTC_SEG2_SRC_SEL, 0xf,
+			OPTC_SEG3_SRC_SEL, 0xf,
+			OPTC_NUM_OF_INPUT_SEGMENT, 0);
+
 	REG_UPDATE(CONTROL,
 			VTG0_ENABLE, 0);
 
diff --git a/drivers/gpu/drm/amd/display/dc/optc/dcn35/dcn35_optc.c b/drivers/gpu/drm/amd/display/dc/optc/dcn35/dcn35_optc.c
index a4a39f1638cf..08a59cf449ca 100644
--- a/drivers/gpu/drm/amd/display/dc/optc/dcn35/dcn35_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/optc/dcn35/dcn35_optc.c
@@ -144,6 +144,13 @@ static bool optc35_disable_crtc(struct timing_generator *optc)
 	REG_UPDATE(OTG_CONTROL,
 			OTG_MASTER_EN, 0);
 
+	REG_UPDATE_5(OPTC_DATA_SOURCE_SELECT,
+			OPTC_SEG0_SRC_SEL, 0xf,
+			OPTC_SEG1_SRC_SEL, 0xf,
+			OPTC_SEG2_SRC_SEL, 0xf,
+			OPTC_SEG3_SRC_SEL, 0xf,
+			OPTC_NUM_OF_INPUT_SEGMENT, 0);
+
 	REG_UPDATE(CONTROL,
 			VTG0_ENABLE, 0);
 
-- 
2.37.3