drm/amd/display: use dispclk AVFS for dppclk

[Why]
There is using pixelclk AVFS for dppclk, that would cause issue.

[How]
To use dispclk AVFS for both dispclk and dppclk.  There would choose
dppclk for request voltage when dispclk wouldn't be updated case.  If
dispclk need to be updated, then it'll choose the bigger one from dppclk
and dispclk for request voltage.
Signed-off-by: Brandon Syu <Brandon.Syu@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c

@@ -234,20 +234,26 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
 			dpp_clock_lowered = true;
 		clk_mgr->base.clks.dppclk_khz = new_clocks->dppclk_khz;
 
-		if (pp_smu && pp_smu->set_voltage_by_freq)
-			pp_smu->set_voltage_by_freq(&pp_smu->pp_smu, PP_SMU_NV_PIXELCLK, clk_mgr_base->clks.dppclk_khz / 1000);
-
 		update_dppclk = true;
 	}
 
 	if (should_set_clock(safe_to_lower, new_clocks->dispclk_khz, clk_mgr_base->clks.dispclk_khz)) {
 		clk_mgr_base->clks.dispclk_khz = new_clocks->dispclk_khz;
-		if (pp_smu && pp_smu->set_voltage_by_freq)
-			pp_smu->set_voltage_by_freq(&pp_smu->pp_smu, PP_SMU_NV_DISPCLK, clk_mgr_base->clks.dispclk_khz / 1000);
 
 		update_dispclk = true;
 	}
 
+	if (update_dppclk || update_dispclk) {
+		new_clocks->disp_dpp_voltage_level_khz = new_clocks->dppclk_khz;
+
+		if (update_dispclk)
+			new_clocks->disp_dpp_voltage_level_khz = new_clocks->dispclk_khz > new_clocks->dppclk_khz ? new_clocks->dispclk_khz : new_clocks->dppclk_khz;
+
+		clk_mgr_base->clks.disp_dpp_voltage_level_khz = new_clocks->disp_dpp_voltage_level_khz;
+		if (pp_smu && pp_smu->set_voltage_by_freq)
+			pp_smu->set_voltage_by_freq(&pp_smu->pp_smu, PP_SMU_NV_DISPCLK, clk_mgr_base->clks.disp_dpp_voltage_level_khz / 1000);
+	}
+
 	if (dc->config.forced_clocks == false || (force_reset && safe_to_lower)) {
 		if (dpp_clock_lowered) {
 			// if clock is being lowered, increase DTO before lowering refclk
@@ -403,6 +409,8 @@ static bool dcn2_are_clock_states_equal(struct dc_clocks *a,
 		return false;
 	else if (a->dppclk_khz != b->dppclk_khz)
 		return false;
+	else if (a->disp_dpp_voltage_level_khz != b->disp_dpp_voltage_level_khz)
+		return false;
 	else if (a->dcfclk_khz != b->dcfclk_khz)
 		return false;
 	else if (a->socclk_khz != b->socclk_khz)

drivers/gpu/drm/amd/display/dc/dc.h

@@ -337,6 +337,7 @@ enum dcn_pwr_state {
 struct dc_clocks {
 	int dispclk_khz;
 	int dppclk_khz;
+	int disp_dpp_voltage_level_khz;
 	int dcfclk_khz;
 	int socclk_khz;
 	int dcfclk_deep_sleep_khz;