[PATCH 1/2] drm/amdgpu: Use mod_delayed_work in amdgpu_gfx_off_ctrl

[Michel Dänzer]

From: Michel Dänzer <mdaenzer at redhat.com>

In contrast to schedule_delayed_work, this pushes back the work if it
was already scheduled before. Specific behaviour change:

Before:

amdgpu_device_delay_enable_gfx_off ran ~100 ms after the first time
GFXOFF was disabled and re-enabled, even if GFXOFF was disabled and
re-enabled again during those 100 ms.

After:

amdgpu_device_delay_enable_gfx_off runs ~100 ms after the last time
GFXOFF is disabled and re-enabled.

The former resulted in frame drops / stutter with the upcoming mutter
41 release on Navi 14, due to constantly enabling GFXOFF in the HW and
disabling it again (for getting the GPU clock counter).

Signed-off-by: Michel Dänzer <mdaenzer at redhat.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index a0be0772c8b3..9cfef56b2aee 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -569,7 +569,7 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable)
 		adev->gfx.gfx_off_req_count--;
 
 	if (enable && !adev->gfx.gfx_off_state && !adev->gfx.gfx_off_req_count) {
-		schedule_delayed_work(&adev->gfx.gfx_off_delay_work, GFX_OFF_DELAY_ENABLE);
+		mod_delayed_work(system_wq, &adev->gfx.gfx_off_delay_work, GFX_OFF_DELAY_ENABLE);
 	} else if (!enable && adev->gfx.gfx_off_state) {
 		if (!amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GFX, false)) {
 			adev->gfx.gfx_off_state = false;
-- 
2.32.0