[PATCH 451/459] drm/amd/display: update DCN2 uclk switch time

[Alex Deucher]

From: Jun Lei <Jun.Lei at amd.com>

[why]
value commited to by HW team is going to be higher
than pre-silicon, and will cause underflow if driver not
updated

[how]
update hardcoded value, update pstate switching logic
to fix case where with long uclk time we won't allow switch
even when we should

Signed-off-by: Jun Lei <Jun.Lei at amd.com>
Reviewed-by: Eric Yang <eric.yang2 at amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 .../gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c  | 8 +++-----
 drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h  | 6 ++++++
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
index e3c1debf2597..6f01830fc020 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
@@ -195,12 +195,10 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
 			pp_smu->set_hard_min_socclk_by_freq(&pp_smu->pp_smu, clk_mgr_base->clks.socclk_khz / 1000);
 	}
 
-	if (!safe_to_lower && pp_smu && pp_smu->set_pstate_handshake_support) {
-		clk_mgr_base->clks.p_state_change_support = false;
-		pp_smu->set_pstate_handshake_support(&pp_smu->pp_smu, false);
-	} else if (safe_to_lower && pp_smu && pp_smu->set_pstate_handshake_support) {
+	if (should_update_pstate_support(safe_to_lower, new_clocks->p_state_change_support, clk_mgr_base->clks.p_state_change_support)) {
 		clk_mgr_base->clks.p_state_change_support = new_clocks->p_state_change_support;
-		pp_smu->set_pstate_handshake_support(&pp_smu->pp_smu, clk_mgr_base->clks.p_state_change_support);
+		if (pp_smu && pp_smu->set_pstate_handshake_support)
+			pp_smu->set_pstate_handshake_support(&pp_smu->pp_smu, clk_mgr_base->clks.p_state_change_support);
 	}
 
 	if (should_set_clock(safe_to_lower, new_clocks->dramclk_khz, clk_mgr_base->clks.dramclk_khz)) {
diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h b/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h
index c322e4697242..0835ac041acf 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h
@@ -274,6 +274,12 @@ static inline bool should_set_clock(bool safe_to_lower, int calc_clk, int cur_cl
 	return ((safe_to_lower && calc_clk < cur_clk) || calc_clk > cur_clk);
 }
 
+static inline bool should_update_pstate_support(bool safe_to_lower, bool calc_support, bool cur_support)
+{
+	// Whenever we are transitioning pstate support, we always want to notify prior to committing state
+	return (calc_support != cur_support) ? !safe_to_lower : false;
+}
+
 int clk_mgr_helper_get_active_display_cnt(
 		struct dc *dc,
 		struct dc_state *context);
-- 
2.20.1