[PATCH 5.3 164/193] drm/amdgpu/sdma5: do not execute 0-sized IBs (v2)

[Greg Kroah-Hartman]

From: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@xxxxxxx>

[ Upstream commit 9bdf63d3579e36942f4b91d3558a90da8116bb40 ]

This seems to help with https://bugs.freedesktop.org/show_bug.cgi?id=111481.

v2: insert a NOP instead of skipping all 0-sized IBs to avoid breaking older hw

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@xxxxxxx>
Reviewed-by: Christian KÃnig <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
index 5eeb72fcc123a..6a51e6a4a035b 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v10_0.c
@@ -264,6 +264,7 @@ static void gmc_v10_0_flush_gpu_tlb(struct amdgpu_device *adev,
 
 	job->vm_pd_addr = amdgpu_gmc_pd_addr(adev->gart.bo);
 	job->vm_needs_flush = true;
+	job->ibs->ptr[job->ibs->length_dw++] = ring->funcs->nop;
 	amdgpu_ring_pad_ib(ring, &job->ibs[0]);
 	r = amdgpu_job_submit(job, &adev->mman.entity,
 			      AMDGPU_FENCE_OWNER_UNDEFINED, &fence);
-- 
2.20.1