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 *