[PATCH 2/2] dmr/amdgpu: Move old fence waiting before reservation lock is aquired.

[Andrey Grodzovsky]

From: Andrey Grodzovsky <Andrey.Grodzovsky at amd.com>

This allows to avoid deadlock during GPU reset.

Change-Id: I817e351b02e653f078063c57cec8a0d94062de12
Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c  | 15 +++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c |  8 ++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 0fa1bc7..79fefc8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -931,6 +931,9 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev,
 {
 	int i, j;
 	int r, ce_preempt = 0, de_preempt = 0;
+	struct amdgpu_ctx_ring *cring;
+	unsigned idx = 0;
+	struct dma_fence *other = NULL;
 
 	for (i = 0, j = 0; i < parser->nchunks && j < parser->job->num_ibs; i++) {
 		struct amdgpu_cs_chunk *chunk;
@@ -983,6 +986,18 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev,
 	    parser->job->ring->funcs->type == AMDGPU_RING_TYPE_VCE))
 		return -EINVAL;
 
+	cring = &parser->ctx->rings[parser->job->ring->idx];
+	idx = cring->sequence & (amdgpu_sched_jobs - 1);
+	other = cring->fences[idx];
+	if (other) {
+		signed long r;
+		r = dma_fence_wait_timeout(other, false, MAX_SCHEDULE_TIMEOUT);
+		if (r < 0) {
+			DRM_ERROR("Error (%ld) waiting for fence!\n", r);
+			return r;
+		}
+	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index c073a68..758b643 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -260,12 +260,8 @@ uint64_t amdgpu_ctx_add_fence(struct amdgpu_ctx *ctx, struct amdgpu_ring *ring,
 
 	idx = seq & (amdgpu_sched_jobs - 1);
 	other = cring->fences[idx];
-	if (other) {
-		signed long r;
-		r = dma_fence_wait_timeout(other, false, MAX_SCHEDULE_TIMEOUT);
-		if (r < 0)
-			DRM_ERROR("Error (%ld) waiting for fence!\n", r);
-	}
+	if (other)
+		BUG_ON(!dma_fence_is_signaled(other));
 
 	dma_fence_get(fence);
 
-- 
2.7.4