linux-kernel - [PATCH AUTOSEL 5.4 012/108] drm/amd/display: Explicitly disable triplebuffer flips

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Date:   Sat, 11 Apr 2020 19:08:07 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Nicholas Kazlauskas <nicholas.kazlauskas@....com>,
        Hersen Wu <hersenxs.wu@....com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Sasha Levin <sashal@...nel.org>, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.4 012/108] drm/amd/display: Explicitly disable triplebuffer flips

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

[ Upstream commit 2d673560b7b83f8fe4163610f35c51b4d095525c ]

[Why]
This is enabled by default on Renoir but there's userspace/API support
to actually make use of this.

Since we're not passing this down through surface updates, let's
explicitly disable this for now.

This fixes "dcn20_program_front_end_for_ctx" warnings associated with
incorrect/unexpected programming sequences performed while this is
enabled.

[How]
Disable it at the topmost level in DM in case anyone tries to flip this
to enabled for any of the other ASICs like Navi10/14.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@....com>
Reviewed-by: Hersen Wu <hersenxs.wu@....com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 360c87ba45956..1b54744b1ba07 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2391,6 +2391,9 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
 	if (adev->asic_type != CHIP_CARRIZO && adev->asic_type != CHIP_STONEY)
 		dm->dc->debug.disable_stutter = amdgpu_pp_feature_mask & PP_STUTTER_MODE ? false : true;
 
+	/* No userspace support. */
+	dm->dc->debug.disable_tri_buf = true;
+
 	return 0;
 fail:
 	kfree(aencoder);
-- 
2.20.1