[PATCH 10/11] drm/amd/display: Disable stutter when programming watermarks on dcn32

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

From: Dillon Varone <Dillon.Varone@amd.com>

[WHY&HOW]
Reprogramming watermarks with stutter allowed can cause instability on
some ASICs. Disable it prior to raising watermarks (prepare bandwidth),
then re-enable after lowering (optimize bandwidth).

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
---
 drivers/gpu/drm/amd/display/dc/dc.h           |  1 +
 .../display/dc/hubbub/dcn32/dcn32_hubbub.c    | 37 ++++++++++++++++---
 .../dc/resource/dcn32/dcn32_resource.c        |  1 +
 .../dc/resource/dcn32/dcn32_resource.h        |  3 +-
 4 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 09d705cf5c9b..d32304443abc 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -1163,6 +1163,7 @@ struct dc_debug_options {
 	unsigned int auxless_alpm_lfps_t1t2_us;
 	short auxless_alpm_lfps_t1t2_offset_us;
 	bool enable_pg_cntl_debug_logs;
+	bool disable_stutter_for_wm_program;
 };
 
 
diff --git a/drivers/gpu/drm/amd/display/dc/hubbub/dcn32/dcn32_hubbub.c b/drivers/gpu/drm/amd/display/dc/hubbub/dcn32/dcn32_hubbub.c
index 92957398ac0a..3b71bfaca291 100644
--- a/drivers/gpu/drm/amd/display/dc/hubbub/dcn32/dcn32_hubbub.c
+++ b/drivers/gpu/drm/amd/display/dc/hubbub/dcn32/dcn32_hubbub.c
@@ -28,6 +28,7 @@
 #include "dcn32_hubbub.h"
 #include "dm_services.h"
 #include "reg_helper.h"
+#include "dal_asic_id.h"
 
 
 #define CTX \
@@ -72,6 +73,14 @@ static void dcn32_init_crb(struct hubbub *hubbub)
 	REG_UPDATE(DCHUBBUB_DEBUG_CTRL_0, DET_DEPTH, 0x47F);
 }
 
+static void hubbub32_set_sdp_control(struct hubbub *hubbub, bool dc_control)
+{
+	struct dcn20_hubbub *hubbub2 = TO_DCN20_HUBBUB(hubbub);
+
+	REG_UPDATE(DCHUBBUB_SDPIF_CFG0,
+			SDPIF_PORT_CONTROL, dc_control);
+}
+
 void hubbub32_set_request_limit(struct hubbub *hubbub, int memory_channel_count, int words_per_channel)
 {
 	struct dcn20_hubbub *hubbub2 = TO_DCN20_HUBBUB(hubbub);
@@ -754,8 +763,17 @@ static bool hubbub32_program_watermarks(
 		unsigned int refclk_mhz,
 		bool safe_to_lower)
 {
+	struct dc *dc = hubbub->ctx->dc;
 	bool wm_pending = false;
 
+	if (!safe_to_lower && dc->debug.disable_stutter_for_wm_program &&
+			(ASICREV_IS_GC_11_0_0(dc->ctx->asic_id.hw_internal_rev) ||
+			ASICREV_IS_GC_11_0_3(dc->ctx->asic_id.hw_internal_rev))) {
+		/* before raising watermarks, SDP control give to DF, stutter must be disabled */
+		hubbub32_set_sdp_control(hubbub, false);
+		hubbub1_allow_self_refresh_control(hubbub, false);
+	}
+
 	if (hubbub32_program_urgent_watermarks(hubbub, watermarks, refclk_mhz, safe_to_lower))
 		wm_pending = true;
 
@@ -786,10 +804,20 @@ static bool hubbub32_program_watermarks(
 	REG_UPDATE(DCHUBBUB_ARB_DF_REQ_OUTSTAND,
 			DCHUBBUB_ARB_MIN_REQ_OUTSTAND, 0x1FF);*/
 
-	if (safe_to_lower || hubbub->ctx->dc->debug.disable_stutter)
-		hubbub1_allow_self_refresh_control(hubbub, !hubbub->ctx->dc->debug.disable_stutter);
+	if (safe_to_lower) {
+		/* after lowering watermarks, stutter setting is restored, SDP control given to DC */
+		hubbub1_allow_self_refresh_control(hubbub, !dc->debug.disable_stutter);
+
+		if (dc->debug.disable_stutter_for_wm_program &&
+				(ASICREV_IS_GC_11_0_0(dc->ctx->asic_id.hw_internal_rev) ||
+				ASICREV_IS_GC_11_0_3(dc->ctx->asic_id.hw_internal_rev))) {
+			hubbub32_set_sdp_control(hubbub, true);
+		}
+	} else if (dc->debug.disable_stutter) {
+		hubbub1_allow_self_refresh_control(hubbub, !dc->debug.disable_stutter);
+	}
 
-	hubbub32_force_usr_retraining_allow(hubbub, hubbub->ctx->dc->debug.force_usr_allow);
+	hubbub32_force_usr_retraining_allow(hubbub, dc->debug.force_usr_allow);
 
 	return wm_pending;
 }
@@ -974,8 +1002,7 @@ void hubbub32_init(struct hubbub *hubbub)
 	ignore the "df_pre_cstate_req" from the SDP port control.
 	only the DCN will determine when to connect the SDP port
 	*/
-	REG_UPDATE(DCHUBBUB_SDPIF_CFG0,
-			SDPIF_PORT_CONTROL, 1);
+	hubbub32_set_sdp_control(hubbub, true);
 	/*Set SDP's max outstanding request to 512
 	must set the register back to 0 (max outstanding = 256) in zero frame buffer mode*/
 	REG_UPDATE(DCHUBBUB_SDPIF_CFG1,
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
index 9917b366f00c..e81b9a0499d2 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c
@@ -739,6 +739,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.fpo_vactive_min_active_margin_us = 200,
 	.fpo_vactive_max_blank_us = 1000,
 	.enable_legacy_fast_update = false,
+	.disable_stutter_for_wm_program = true
 };
 
 static struct dce_aux *dcn32_aux_engine_create(
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.h b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.h
index 20d714596021..99f0432288b4 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.h
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.h
@@ -1230,7 +1230,8 @@ unsigned int dcn32_get_max_hw_cursor_size(const struct dc *dc,
       SR(DCHUBBUB_ARB_MALL_CNTL),                                              \
       SR(DCN_VM_FAULT_ADDR_MSB), SR(DCN_VM_FAULT_ADDR_LSB),                    \
       SR(DCN_VM_FAULT_CNTL), SR(DCN_VM_FAULT_STATUS),                          \
-      SR(SDPIF_REQUEST_RATE_LIMIT)
+      SR(SDPIF_REQUEST_RATE_LIMIT),                                            \
+      SR(DCHUBBUB_SDPIF_CFG0)
 
 /* DCCG */
 
-- 
2.43.0