linux-kernel - [PATCH AUTOSEL 6.14 637/642] drm/amd/display: Exit idle optimizations before accessing PHY

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Message-Id: <20250505221419.2672473-637-sashal@kernel.org>
Date: Mon,  5 May 2025 18:14:13 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Ovidiu Bunea <Ovidiu.Bunea@....com>,
	Charlene Liu <charlene.liu@....com>,
	Roman Li <roman.li@....com>,
	Daniel Wheeler <daniel.wheeler@....com>,
	Alex Deucher <alexander.deucher@....com>,
	Sasha Levin <sashal@...nel.org>,
	harry.wentland@....com,
	sunpeng.li@....com,
	christian.koenig@....com,
	airlied@...il.com,
	simona@...ll.ch,
	Charlene.Liu@....com,
	alvin.lee2@....com,
	chiahsuan.chung@....com,
	jerry.zuo@....com,
	alex.hung@....com,
	Kaitlyn.Tse@....com,
	ryanseto@....com,
	martin.tsai@....com,
	yi-lchen@....com,
	tjakobi@...h.uni-bielefeld.de,
	Sungjoon.Kim@....com,
	michael.strauss@....com,
	Brandon.Syu@....com,
	amd-gfx@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 6.14 637/642] drm/amd/display: Exit idle optimizations before accessing PHY

From: Ovidiu Bunea <Ovidiu.Bunea@....com>

[ Upstream commit c488967488d7eff7b9c527d5469c424c15377502 ]

[why & how]
By default, DCN HW is in idle optimized state which does not allow access
to PHY registers. If BIOS powers up the DCN, it is fine because they will
power up everything. Only exit idle optimized state when not taking control
from VBIOS.

Fixes: be704e5ef4bd ("Revert "drm/amd/display: Exit idle optimizations before attempt to access PHY"")
Reviewed-by: Charlene Liu <charlene.liu@....com>
Signed-off-by: Ovidiu Bunea <Ovidiu.Bunea@....com>
Signed-off-by: Roman Li <roman.li@....com>
Tested-by: Daniel Wheeler <daniel.wheeler@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
index 2f5f3e749a1ab..94ceccfc04982 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
@@ -1889,6 +1889,7 @@ void dce110_enable_accelerated_mode(struct dc *dc, struct dc_state *context)
 	bool can_apply_edp_fast_boot = false;
 	bool can_apply_seamless_boot = false;
 	bool keep_edp_vdd_on = false;
+	struct dc_bios *dcb = dc->ctx->dc_bios;
 	DC_LOGGER_INIT();
 
 
@@ -1965,6 +1966,8 @@ void dce110_enable_accelerated_mode(struct dc *dc, struct dc_state *context)
 			hws->funcs.edp_backlight_control(edp_link_with_sink, false);
 		}
 		/*resume from S3, no vbios posting, no need to power down again*/
+		if (dcb && dcb->funcs && !dcb->funcs->is_accelerated_mode(dcb))
+			clk_mgr_exit_optimized_pwr_state(dc, dc->clk_mgr);
 
 		power_down_all_hw_blocks(dc);
 
@@ -1977,6 +1980,8 @@ void dce110_enable_accelerated_mode(struct dc *dc, struct dc_state *context)
 		disable_vga_and_power_gate_all_controllers(dc);
 		if (edp_link_with_sink && !keep_edp_vdd_on)
 			dc->hwss.edp_power_control(edp_link_with_sink, false);
+		if (dcb && dcb->funcs && !dcb->funcs->is_accelerated_mode(dcb))
+			clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);
 	}
 	bios_set_scratch_acc_mode_change(dc->ctx->dc_bios, 1);
 }
-- 
2.39.5