[PATCH] drm/amdgpu/display: Only set vblank_disable_immediate when PSR is not enabled

[Deucher, Alexander]

[Public]

Acked-by: Alex Deucher <alexander.deucher at amd.com>
________________________________
From: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Sent: Tuesday, November 30, 2021 9:53 AM
To: amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>
Cc: Kazlauskas, Nicholas <Nicholas.Kazlauskas at amd.com>; Wentland, Harry <Harry.Wentland at amd.com>; Deucher, Alexander <Alexander.Deucher at amd.com>
Subject: [PATCH] drm/amdgpu/display: Only set vblank_disable_immediate when PSR is not enabled

[Why]
PSR currently relies on the kernel's delayed vblank on/off mechanism
as an implicit bufferring mechanism to prevent excessive entry/exit.

Without this delay the user experience is impacted since it can take
a few frames to enter/exit.

[How]
Only allow vblank disable immediate for DC when psr is not supported.

Leave a TODO indicating that this support should be extended in the
future to delay independent of the vblank interrupt.

Fixes: 3d1508b73ff1 ("drm/amdgpu/display: set vblank_disable_immediate for DC")

Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

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 0747dc7922c2..d582d44c02ad 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1599,9 +1599,6 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
         adev_to_drm(adev)->mode_config.cursor_width = adev->dm.dc->caps.max_cursor_size;
         adev_to_drm(adev)->mode_config.cursor_height = adev->dm.dc->caps.max_cursor_size;

-       /* Disable vblank IRQs aggressively for power-saving */
-       adev_to_drm(adev)->vblank_disable_immediate = true;
-
         if (drm_vblank_init(adev_to_drm(adev), adev->dm.display_indexes_num)) {
                 DRM_ERROR(
                 "amdgpu: failed to initialize sw for display support.\n");
@@ -4264,6 +4261,14 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)

         }

+       /*
+        * Disable vblank IRQs aggressively for power-saving.
+        *
+        * TODO: Fix vblank control helpers to delay PSR entry to allow this when PSR
+        * is also supported.
+        */
+       adev_to_drm(adev)->vblank_disable_immediate = !psr_feature_enabled;
+
         /* Software is initialized. Now we can register interrupt handlers. */
         switch (adev->asic_type) {
 #if defined(CONFIG_DRM_AMD_DC_SI)
--
2.25.1

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