linux-kernel - [PATCH AUTOSEL 5.19 060/105] drm/amd/display: disable otg toggle w/a on boot

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Date:   Thu, 11 Aug 2022 11:27:44 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Dmytro Laktyushkin <Dmytro.Laktyushkin@....com>,
        Charlene Liu <Charlene.Liu@....com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@....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, Xinhui.Pan@....com,
        airlied@...ux.ie, daniel@...ll.ch, nicholas.kazlauskas@....com,
        qingqing.zhuo@....com, paul.hsieh@....com, Eric.Yang2@....com,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.19 060/105] drm/amd/display: disable otg toggle w/a on boot

From: Dmytro Laktyushkin <Dmytro.Laktyushkin@....com>

[ Upstream commit 8a077d9caa3a274de36ee2fe7b608041f5690343 ]

This w/a has a bad interaction with seamless boot toggling an
active stream. Most panels recover, however some fail leading
to display corruption.

Reviewed-by: Charlene Liu <Charlene.Liu@....com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@....com>
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@....com>
Tested-by: Daniel Wheeler <daniel.wheeler@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 .../gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c
index f4381725b210..36b0cd47c1c7 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c
@@ -173,11 +173,14 @@ static void dcn315_update_clocks(struct clk_mgr *clk_mgr_base,
 	}
 
 	if (should_set_clock(safe_to_lower, new_clocks->dispclk_khz, clk_mgr_base->clks.dispclk_khz)) {
-		dcn315_disable_otg_wa(clk_mgr_base, true);
+		/* No need to apply the w/a if we haven't taken over from bios yet */
+		if (clk_mgr_base->clks.dispclk_khz)
+			dcn315_disable_otg_wa(clk_mgr_base, true);
 
 		clk_mgr_base->clks.dispclk_khz = new_clocks->dispclk_khz;
 		dcn315_smu_set_dispclk(clk_mgr, clk_mgr_base->clks.dispclk_khz);
-		dcn315_disable_otg_wa(clk_mgr_base, false);
+		if (clk_mgr_base->clks.dispclk_khz)
+			dcn315_disable_otg_wa(clk_mgr_base, false);
 
 		update_dispclk = true;
 	}
-- 
2.35.1