Commit 08da1821 authored by Hamza Mahfooz's avatar Hamza Mahfooz Committed by Alex Deucher
Browse files

drm/amd/display: fix flickering caused by S/G mode 

Currently, on a handful of ASICs. We allow the framebuffer for a given
plane to exist in either VRAM or GTT. However, if the plane's new
framebuffer is in a different memory domain than it's previous
framebuffer, flipping between them can cause the screen to flicker. So,
to fix this, don't perform an immediate flip in the aforementioned case.

Cc: stable@vger.kernel.org
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2354


Reviewed-by: default avatarRoman Li <Roman.Li@amd.com>
Fixes: 81d0bcf9 ("drm/amdgpu: make display pinning more flexible (v2)")
Signed-off-by: default avatarHamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 9675b3ba

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+11 −2
Original line number Diff line number Diff line
@@ -7901,6 +7901,13 @@ static void amdgpu_dm_commit_cursors(struct drm_atomic_state *state) 
			amdgpu_dm_plane_handle_cursor_update(plane, old_plane_state);

}



static inline uint32_t get_mem_type(struct drm_framebuffer *fb)

{

	struct amdgpu_bo *abo = gem_to_amdgpu_bo(fb->obj[0]);



	return abo->tbo.resource ? abo->tbo.resource->mem_type : 0;

}



static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,

				    struct dc_state *dc_state,

				    struct drm_device *dev,
@@ -8043,11 +8050,13 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, 


		/*

		 * Only allow immediate flips for fast updates that don't

		 * change FB pitch, DCC state, rotation or mirroing.

		 * change memory domain, FB pitch, DCC state, rotation or

		 * mirroring.

		 */

		bundle->flip_addrs[planes_count].flip_immediate =

			crtc->state->async_flip &&

			acrtc_state->update_type == UPDATE_TYPE_FAST;

			acrtc_state->update_type == UPDATE_TYPE_FAST &&

			get_mem_type(old_plane_state->fb) == get_mem_type(fb);



		timestamp_ns = ktime_get_ns();

		bundle->flip_addrs[planes_count].flip_timestamp_in_us = div_u64(timestamp_ns, 1000);