This is a note to let you know that I've just added the patch titled drm/amdgpu: remove unsafe optimization to drop preamble ib to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amdgpu-remove-unsafe-optimization-to-drop-preamb.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8d5c4118bf552a0ef2dd3bd6f8b57cc57cf6bf98 Author: Jiansong Chen <Jiansong.Chen@xxxxxxx> Date: Thu May 13 10:56:50 2021 +0800 drm/amdgpu: remove unsafe optimization to drop preamble ib [ Upstream commit 7d9c70d23550eb86a1bec1954ccaa8d6ec3a3328 ] Take the situation with gfxoff, the optimization may cause corrupt CE ram contents. In addition emit_cntxcntl callback has similar optimization which firmware can handle properly even for power feature. Signed-off-by: Jiansong Chen <Jiansong.Chen@xxxxxxx> Reviewed-by: Hawking Zhang <Hawking.Zhang@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c index 28f20f0b722f..163188ce02bd 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c @@ -128,7 +128,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs, struct amdgpu_device *adev = ring->adev; struct amdgpu_ib *ib = &ibs[0]; struct dma_fence *tmp = NULL; - bool skip_preamble, need_ctx_switch; + bool need_ctx_switch; unsigned patch_offset = ~0; struct amdgpu_vm *vm; uint64_t fence_ctx; @@ -221,7 +221,6 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs, if (need_ctx_switch) status |= AMDGPU_HAVE_CTX_SWITCH; - skip_preamble = ring->current_ctx == fence_ctx; if (job && ring->funcs->emit_cntxcntl) { status |= job->preamble_status; status |= job->preemption_status; @@ -239,14 +238,6 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs, for (i = 0; i < num_ibs; ++i) { ib = &ibs[i]; - /* drop preamble IBs if we don't have a context switch */ - if ((ib->flags & AMDGPU_IB_FLAG_PREAMBLE) && - skip_preamble && - !(status & AMDGPU_PREAMBLE_IB_PRESENT_FIRST) && - !amdgpu_mcbp && - !amdgpu_sriov_vf(adev)) /* for SRIOV preemption, Preamble CE ib must be inserted anyway */ - continue; - if (job && ring->funcs->emit_frame_cntl) { if (secure != !!(ib->flags & AMDGPU_IB_FLAGS_SECURE)) { amdgpu_ring_emit_frame_cntl(ring, false, secure);