linux-kernel - [PATCH AUTOSEL 6.2 09/60] drm/amd/display: Defer DIG FIFO disable after VID stream enable

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Message-Id: <20230227020045.1045105-9-sashal@kernel.org>
Date:   Sun, 26 Feb 2023 20:59:54 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Nicholas Kazlauskas <nicholas.kazlauskas@....com>,
        Aurabindo Pillai <aurabindo.pillai@....com>,
        Syed Hassan <Syed.Hassan@....com>,
        Daniel Wheeler <daniel.wheeler@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Sasha Levin <sashal@...nel.org>, harry.wentland@....com,
        sunpeng.li@....com, Rodrigo.Siqueira@....com,
        christian.koenig@....com, Xinhui.Pan@....com, airlied@...il.com,
        daniel@...ll.ch, HaoPing.Liu@....com, Charlene.Liu@....com,
        wenjing.liu@....com, sancchen@....com,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 6.2 09/60] drm/amd/display: Defer DIG FIFO disable after VID stream enable

From: Nicholas Kazlauskas <nicholas.kazlauskas@....com>

[ Upstream commit 2d90a1c054831338d57b39aec4d273cf3e867590 ]

[Why]
On some monitors we see a brief flash of corruption during the
monitor disable sequence caused by FIFO being disabled in the middle
of an active DP stream.

[How]
Wait until DP vid stream is disabled before turning off the FIFO.

The FIFO reset on DP unblank should take care of clearing any FIFO
error, if any.

Acked-by: Aurabindo Pillai <aurabindo.pillai@....com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@....com>
Reviewed-by: Syed Hassan <Syed.Hassan@....com>
Tested-by: Daniel Wheeler <daniel.wheeler@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 .../drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c   | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
index 38842f938bed0..0926db0183383 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
@@ -278,10 +278,10 @@ static void enc314_stream_encoder_dp_blank(
 	struct dc_link *link,
 	struct stream_encoder *enc)
 {
-	/* New to DCN314 - disable the FIFO before VID stream disable. */
-	enc314_disable_fifo(enc);
-
 	enc1_stream_encoder_dp_blank(link, enc);
+
+	/* Disable FIFO after the DP vid stream is disabled to avoid corruption. */
+	enc314_disable_fifo(enc);
 }
 
 static void enc314_stream_encoder_dp_unblank(
-- 
2.39.0