This is super simple elimination of else branch and I should
probably even use unlikely in
if (ring->count_dw < count_dw) {
However, amdgpu_ring_write() has similar if condition, but does not
return after DRM_ERROR and it looks suspicious. On error, we still
adding v to ring and keeping count_dw-- below zero.
if (ring->count_dw <= 0)
DRM_ERROR("amdgpu: writing more dwords to the ring than expected!\n");
ring->ring[ring->wptr++] = v;
ring->wptr &= ring->ptr_mask;
ring->count_dw--;
I can obviously be totaly wrong. Hmm?
--------8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index c1b913541739..c6f4f874ea68 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1596,28 +1596,29 @@ static inline void amdgpu_ring_write_multiple(struct amdgpu_ring *ring, void *sr
if (ring->count_dw < count_dw) {
DRM_ERROR("amdgpu: writing more dwords to the ring than expected!\n");
- } else {
- occupied = ring->wptr & ring->ptr_mask;
- dst = (void *)&ring->ring[occupied];
- chunk1 = ring->ptr_mask + 1 - occupied;
- chunk1 = (chunk1 >= count_dw) ? count_dw: chunk1;
- chunk2 = count_dw - chunk1;
- chunk1 <<= 2;
- chunk2 <<= 2;
-
- if (chunk1)
- memcpy(dst, src, chunk1);
-
- if (chunk2) {
- src += chunk1;
- dst = (void *)ring->ring;
- memcpy(dst, src, chunk2);
- }
-
- ring->wptr += count_dw;
- ring->wptr &= ring->ptr_mask;
- ring->count_dw -= count_dw;
+ return;
}
+
+ occupied = ring->wptr & ring->ptr_mask;
+ dst = (void *)&ring->ring[occupied];
+ chunk1 = ring->ptr_mask + 1 - occupied;
+ chunk1 = (chunk1 >= count_dw) ? count_dw: chunk1;
+ chunk2 = count_dw - chunk1;
+ chunk1 <<= 2;
+ chunk2 <<= 2;
+
+ if (chunk1)
+ memcpy(dst, src, chunk1);
+
+ if (chunk2) {
+ src += chunk1;
+ dst = (void *)ring->ring;
+ memcpy(dst, src, chunk2);
+ }
+
+ ring->wptr += count_dw;
+ ring->wptr &= ring->ptr_mask;
+ ring->count_dw -= count_dw;
}
static inline struct amdgpu_sdma_instance *
--
2.12.2
