[PATCH 5.13 063/266] drm/amdgpu: remove unsafe optimization to drop preamble ib

Greg Kroah-Hartman
2021-07-15T19:24:40Z

From: Jiansong Chen <Jiansong.Chen@amd.com>

[ 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@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
index a2fe2dac32c1..98906a43fda3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
@@ -130,7 +130,7 @@ 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;
@@ -227,7 +227,6 @@ 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;
@@ -245,14 +244,6 @@ 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);
--
2.30.2