[PATCH 05/12] drm/amd/display: update dpp/disp clock from smu clock table

Roman.Li at amd.com Roman.Li at amd.com
Wed Jul 30 18:58:56 UTC 2025


From: Paul Hsieh <Paul.Hsieh at amd.com>

[Why]
The reason some high-resolution monitors fail to display properly
is that this platform does not support sufficiently high DPP and
DISP clock frequencies

[How]
Update DISP and DPP clocks from the smu clock table then DML can
filter these mode if not support.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Signed-off-by: Paul Hsieh <Paul.Hsieh at amd.com>
Signed-off-by: Roman Li <roman.li at amd.com>
---
 .../display/dc/clk_mgr/dcn301/vg_clk_mgr.c    | 16 +++++++++++++++
 .../amd/display/dc/dml/dcn301/dcn301_fpu.c    | 20 ++++++++++++++++---
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn301/vg_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn301/vg_clk_mgr.c
index 9e2ef0e724fc..7aee02d56292 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn301/vg_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn301/vg_clk_mgr.c
@@ -563,6 +563,7 @@ static void vg_clk_mgr_helper_populate_bw_params(
 {
 	int i, j;
 	struct clk_bw_params *bw_params = clk_mgr->base.bw_params;
+	uint32_t max_dispclk = 0, max_dppclk = 0;
 
 	j = -1;
 
@@ -584,6 +585,15 @@ static void vg_clk_mgr_helper_populate_bw_params(
 		return;
 	}
 
+	/* dispclk and dppclk can be max at any voltage, same number of levels for both */
+	if (clock_table->NumDispClkLevelsEnabled <= VG_NUM_DISPCLK_DPM_LEVELS &&
+	    clock_table->NumDispClkLevelsEnabled <= VG_NUM_DPPCLK_DPM_LEVELS) {
+		max_dispclk = find_max_clk_value(clock_table->DispClocks, clock_table->NumDispClkLevelsEnabled);
+		max_dppclk = find_max_clk_value(clock_table->DppClocks, clock_table->NumDispClkLevelsEnabled);
+	} else {
+		ASSERT(0);
+	}
+
 	bw_params->clk_table.num_entries = j + 1;
 
 	for (i = 0; i < bw_params->clk_table.num_entries - 1; i++, j--) {
@@ -591,11 +601,17 @@ static void vg_clk_mgr_helper_populate_bw_params(
 		bw_params->clk_table.entries[i].memclk_mhz = clock_table->DfPstateTable[j].memclk;
 		bw_params->clk_table.entries[i].voltage = clock_table->DfPstateTable[j].voltage;
 		bw_params->clk_table.entries[i].dcfclk_mhz = find_dcfclk_for_voltage(clock_table, clock_table->DfPstateTable[j].voltage);
+
+		/* Now update clocks we do read */
+		bw_params->clk_table.entries[i].dispclk_mhz = max_dispclk;
+		bw_params->clk_table.entries[i].dppclk_mhz = max_dppclk;
 	}
 	bw_params->clk_table.entries[i].fclk_mhz = clock_table->DfPstateTable[j].fclk;
 	bw_params->clk_table.entries[i].memclk_mhz = clock_table->DfPstateTable[j].memclk;
 	bw_params->clk_table.entries[i].voltage = clock_table->DfPstateTable[j].voltage;
 	bw_params->clk_table.entries[i].dcfclk_mhz = find_max_clk_value(clock_table->DcfClocks, VG_NUM_DCFCLK_DPM_LEVELS);
+	bw_params->clk_table.entries[i].dispclk_mhz = find_max_clk_value(clock_table->DispClocks, VG_NUM_DISPCLK_DPM_LEVELS);
+	bw_params->clk_table.entries[i].dppclk_mhz = find_max_clk_value(clock_table->DppClocks, VG_NUM_DPPCLK_DPM_LEVELS);
 
 	bw_params->vram_type = bios_info->memory_type;
 	bw_params->num_channels = bios_info->ma_channel_number;
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c
index 0c0b2d67c9cd..2066a65c69bb 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c
@@ -326,7 +326,7 @@ void dcn301_fpu_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_p
 	struct dcn301_resource_pool *pool = TO_DCN301_RES_POOL(dc->res_pool);
 	struct clk_limit_table *clk_table = &bw_params->clk_table;
 	unsigned int i, closest_clk_lvl;
-	int j;
+	int j = 0, max_dispclk_mhz = 0, max_dppclk_mhz = 0;
 
 	dc_assert_fp_enabled();
 
@@ -338,6 +338,15 @@ void dcn301_fpu_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_p
 	dcn3_01_soc.num_chans = bw_params->num_channels;
 
 	ASSERT(clk_table->num_entries);
+
+	/* Prepass to find max clocks independent of voltage level. */
+	for (i = 0; i < clk_table->num_entries; ++i) {
+		if (clk_table->entries[i].dispclk_mhz > max_dispclk_mhz)
+			max_dispclk_mhz = clk_table->entries[i].dispclk_mhz;
+		if (clk_table->entries[i].dppclk_mhz > max_dppclk_mhz)
+			max_dppclk_mhz = clk_table->entries[i].dppclk_mhz;
+	}
+
 	for (i = 0; i < clk_table->num_entries; i++) {
 		/* loop backwards*/
 		for (closest_clk_lvl = 0, j = dcn3_01_soc.num_states - 1; j >= 0; j--) {
@@ -353,8 +362,13 @@ void dcn301_fpu_update_bw_bounding_box(struct dc *dc, struct clk_bw_params *bw_p
 		s[i].socclk_mhz = clk_table->entries[i].socclk_mhz;
 		s[i].dram_speed_mts = clk_table->entries[i].memclk_mhz * 2;
 
-		s[i].dispclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
-		s[i].dppclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
+		/* Clocks independent of voltage level. */
+		s[i].dispclk_mhz = max_dispclk_mhz ? max_dispclk_mhz :
+			dcn3_01_soc.clock_limits[closest_clk_lvl].dispclk_mhz;
+
+		s[i].dppclk_mhz = max_dppclk_mhz ? max_dppclk_mhz :
+			dcn3_01_soc.clock_limits[closest_clk_lvl].dppclk_mhz;
+
 		s[i].dram_bw_per_chan_gbps =
 			dcn3_01_soc.clock_limits[closest_clk_lvl].dram_bw_per_chan_gbps;
 		s[i].dscclk_mhz = dcn3_01_soc.clock_limits[closest_clk_lvl].dscclk_mhz;
-- 
2.34.1



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