drm/amd/display: implement dc_mode_memclk

why:
Need interface to lower clocks when in dc (power save)
mode. Must be able to work with p_state unsupported cases
Can cause flicker when OS notifies us of dc state change

how:
added dal3 interface for KMD
added pathway to query smu for this softmax
added blank before clock change to override underflow
added logic to change clk based on pstatesupport and softmax
added logic in prepare/optimize_bw to conform while changing
clocks

Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Martin Leung <Martin.Leung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 41 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
index 1861a147a7fa..f977f29907df 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
@@ -252,6 +252,7 @@ static void dcn3_update_clocks(struct clk_mgr *clk_mgr_base,
 	bool update_dispclk = false;
 	bool enter_display_off = false;
 	bool dpp_clock_lowered = false;
+	bool update_pstate_unsupported_clk = false;
 	struct dmcu *dmcu = clk_mgr_base->ctx->dc->res_pool->dmcu;
 	bool force_reset = false;
 	bool update_uclk = false;
@@ -299,13 +300,28 @@ static void dcn3_update_clocks(struct clk_mgr *clk_mgr_base,
 	clk_mgr_base->clks.prev_p_state_change_support = clk_mgr_base->clks.p_state_change_support;
 	total_plane_count = clk_mgr_helper_get_active_plane_cnt(dc, context);
 	p_state_change_support = new_clocks->p_state_change_support || (total_plane_count == 0);
-	if (should_update_pstate_support(safe_to_lower, p_state_change_support, clk_mgr_base->clks.p_state_change_support)) {
+
+	// invalidate the current P-State forced min in certain dc_mode_softmax situations
+	if (dc->clk_mgr->dc_mode_softmax_enabled && safe_to_lower && !p_state_change_support) {
+		if ((new_clocks->dramclk_khz <= dc->clk_mgr->bw_params->dc_mode_softmax_memclk * 1000) !=
+				(clk_mgr_base->clks.dramclk_khz <= dc->clk_mgr->bw_params->dc_mode_softmax_memclk * 1000))
+			update_pstate_unsupported_clk = true;
+	}
+
+	if (should_update_pstate_support(safe_to_lower, p_state_change_support, clk_mgr_base->clks.p_state_change_support) ||
+			update_pstate_unsupported_clk) {
 		clk_mgr_base->clks.p_state_change_support = p_state_change_support;
 
 		/* to disable P-State switching, set UCLK min = max */
-		if (!clk_mgr_base->clks.p_state_change_support)
-			dcn30_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK,
+		if (!clk_mgr_base->clks.p_state_change_support) {
+			if (dc->clk_mgr->dc_mode_softmax_enabled &&
+				new_clocks->dramclk_khz <= dc->clk_mgr->bw_params->dc_mode_softmax_memclk * 1000)
+				dcn30_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK,
+					dc->clk_mgr->bw_params->dc_mode_softmax_memclk);
+			else
+				dcn30_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK,
 					clk_mgr_base->bw_params->clk_table.entries[clk_mgr_base->bw_params->clk_table.num_entries - 1].memclk_mhz);
+		}
 	}
 
 	/* Always update saved value, even if new value not set due to P-State switching unsupported */
@@ -421,6 +437,24 @@ static void dcn3_set_hard_max_memclk(struct clk_mgr *clk_mgr_base)
 			clk_mgr_base->bw_params->clk_table.entries[clk_mgr_base->bw_params->clk_table.num_entries - 1].memclk_mhz);
 }
 
+static void dcn3_set_max_memclk(struct clk_mgr *clk_mgr_base, unsigned int memclk_mhz)
+{
+	struct clk_mgr_internal *clk_mgr = TO_CLK_MGR_INTERNAL(clk_mgr_base);
+
+	if (!clk_mgr->smu_present)
+		return;
+
+	dcn30_smu_set_hard_max_by_freq(clk_mgr, PPCLK_UCLK, memclk_mhz);
+}
+static void dcn3_set_min_memclk(struct clk_mgr *clk_mgr_base, unsigned int memclk_mhz)
+{
+	struct clk_mgr_internal *clk_mgr = TO_CLK_MGR_INTERNAL(clk_mgr_base);
+
+	if (!clk_mgr->smu_present)
+		return;
+	dcn30_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK, memclk_mhz);
+}
+
 /* Get current memclk states, update bounding box */
 static void dcn3_get_memclk_states_from_smu(struct clk_mgr *clk_mgr_base)
 {
@@ -436,6 +470,8 @@ static void dcn3_get_memclk_states_from_smu(struct clk_mgr *clk_mgr_base)
 			&num_levels);
 	clk_mgr_base->bw_params->clk_table.num_entries = num_levels ? num_levels : 1;
 
+	clk_mgr_base->bw_params->dc_mode_softmax_memclk = dcn30_smu_get_dc_mode_max_dpm_freq(clk_mgr, PPCLK_UCLK);
+
 	/* Refresh bounding box */
 	clk_mgr_base->ctx->dc->res_pool->funcs->update_bw_bounding_box(
 			clk_mgr->base.ctx->dc, clk_mgr_base->bw_params);
@@ -505,6 +541,8 @@ static struct clk_mgr_funcs dcn3_funcs = {
 		.notify_wm_ranges = dcn3_notify_wm_ranges,
 		.set_hard_min_memclk = dcn3_set_hard_min_memclk,
 		.set_hard_max_memclk = dcn3_set_hard_max_memclk,
+		.set_max_memclk = dcn3_set_max_memclk,
+		.set_min_memclk = dcn3_set_min_memclk,
 		.get_memclk_states_from_smu = dcn3_get_memclk_states_from_smu,
 		.are_clock_states_equal = dcn3_are_clock_states_equal,
 		.enable_pme_wa = dcn3_enable_pme_wa,