amdgpu: fix for submition with no ibs

Avoid a crash if no IBs are specified.

Signed-off-by: Ken Wang <Qingqing.Wang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 9 insertions, 0 deletions

diff --git a/amdgpu/amdgpu_cs.c b/amdgpu/amdgpu_cs.c
index b4f41b0e..fb5b3a8c 100644
--- a/amdgpu/amdgpu_cs.c
+++ b/amdgpu/amdgpu_cs.c
@@ -190,6 +190,10 @@ static int amdgpu_cs_submit_one(amdgpu_context_handle context,
                 return -EINVAL;
         if (ibs_request->number_of_ibs > AMDGPU_CS_MAX_IBS_PER_SUBMIT)
                 return -EINVAL;
+        if (ibs_request->number_of_ibs == 0) {
+                ibs_request->seq_no = AMDGPU_NULL_SUBMIT_SEQ;
+                return 0;
+        }
         user_fence = (ibs_request->fence_info.handle != NULL);
 
         size = ibs_request->number_of_ibs + (user_fence ? 2 : 1) + 1;
@@ -422,6 +426,10 @@ int amdgpu_cs_query_fence_status(struct amdgpu_cs_fence *fence,
                 return -EINVAL;
         if (fence->ring >= AMDGPU_CS_MAX_RINGS)
                 return -EINVAL;
+        if (fence->fence == AMDGPU_NULL_SUBMIT_SEQ) {
+                *expired = true;
+                return 0;
+        }
 
         *expired = false;
 
diff --git a/amdgpu/amdgpu_internal.h b/amdgpu/amdgpu_internal.h
index 557ba1f1..4f039b68 100644
--- a/amdgpu/amdgpu_internal.h
+++ b/amdgpu/amdgpu_internal.h
@@ -44,6 +44,7 @@
 #define ROUND_DOWN(x, y) ((x) & ~__round_mask(x, y))
 
 #define AMDGPU_INVALID_VA_ADDRESS       0xffffffffffffffff
+#define AMDGPU_NULL_SUBMIT_SEQ          0
 
 struct amdgpu_bo_va_hole {
         struct list_head list;