[PATCH AUTOSEL 5.4 050/350] drm/amd/display: Set number of pipes to 1 if the second pipe was disabled

Sasha Levin sashal at kernel.org
Tue Dec 10 21:02:35 UTC 2019

From: Nikola Cornij <nikola.cornij at amd.com>

[ Upstream commit 2fef0faa1cdc5d41ce3ef83f7b8f7e7ecb02d700 ]

Some ODM-related register settings are inconsistently updated by VBIOS, causing
the state in DC to be invalid, which would then end up crashing in certain
use-cases (such as disable/enable device).

Check the enabled status of the second pipe when determining the number of
OPTC sources. If the second pipe is disabled, set the number of sources to 1
regardless of other settings (that may not be updated correctly).

Signed-off-by: Nikola Cornij <nikola.cornij at amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_optc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_optc.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_optc.c
index 2137e2be21404..dda90995ba933 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_optc.c
@@ -287,6 +287,10 @@ void optc2_get_optc_source(struct timing_generator *optc,
 		*num_of_src_opp = 2;
 		*num_of_src_opp = 1;
+	/* Work around VBIOS not updating OPTC_NUM_OF_INPUT_SEGMENT */
+	if (*src_opp_id_1 == 0xf)
+		*num_of_src_opp = 1;
 void optc2_set_dwb_source(struct timing_generator *optc,

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