On 09.09.25 16:49, Timur Kristóf wrote:
> Rename extra_dw to extra_bytes and document what it's for.
>
> The value is already used as if it were bytes in vcn_v4_0.c
> and in amdgpu_ring_init. Just adjust the dword count in
> jpeg_v1_0.c so that it becomes a byte count.
>
> v2:
> Rename extra_dw to extra_bytes as discussed during review.
>
> Fixes: c8c1a1d2ef04 ("drm/amdgpu: define and add extra dword for jpeg ring")
> Signed-off-by: Timur Kristóf <timur.kris...@gmail.com>
Reviewed-by: Christian König <christian.koe...@amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 11 ++++++-----
> drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 13 ++++++++++++-
> drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c | 2 +-
> 4 files changed, 20 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index 6379bb25bf5c..eca8b28e3fb9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -364,11 +364,12 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct
> amdgpu_ring *ring,
>
> /* Allocate ring buffer */
> if (ring->ring_obj == NULL) {
> - r = amdgpu_bo_create_kernel(adev, ring->ring_size +
> ring->funcs->extra_dw, PAGE_SIZE,
> - AMDGPU_GEM_DOMAIN_GTT,
> - &ring->ring_obj,
> - &ring->gpu_addr,
> - (void **)&ring->ring);
> + r = amdgpu_bo_create_kernel(adev, ring->ring_size +
> ring->funcs->extra_bytes,
> + PAGE_SIZE,
> + AMDGPU_GEM_DOMAIN_GTT,
> + &ring->ring_obj,
> + &ring->gpu_addr,
> + (void **)&ring->ring);
> if (r) {
> dev_err(adev->dev, "(%d) ring create failed\n", r);
> kvfree(ring->ring_backup);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index 7670f5d82b9e..12783ea3ba0f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -211,7 +211,18 @@ struct amdgpu_ring_funcs {
> bool support_64bit_ptrs;
> bool no_user_fence;
> bool secure_submission_supported;
> - unsigned extra_dw;
> +
> + /**
> + * @extra_bytes:
> + *
> + * Optional extra space in bytes that is added to the ring size
> + * when allocating the BO that holds the contents of the ring.
> + * This space isn't used for command submission to the ring,
> + * but is just there to satisfy some hardware requirements or
> + * implement workarounds. It's up to the implementation of each
> + * specific ring to initialize this space.
> + */
> + unsigned extra_bytes;
>
> /* ring read/write ptr handling */
> u64 (*get_rptr)(struct amdgpu_ring *ring);
> diff --git a/drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c
> b/drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c
> index 9e428e669ada..b5bb7f4d607c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/jpeg_v1_0.c
> @@ -557,7 +557,7 @@ static const struct amdgpu_ring_funcs
> jpeg_v1_0_decode_ring_vm_funcs = {
> .nop = PACKET0(0x81ff, 0),
> .support_64bit_ptrs = false,
> .no_user_fence = true,
> - .extra_dw = 64,
> + .extra_bytes = 256,
> .get_rptr = jpeg_v1_0_decode_ring_get_rptr,
> .get_wptr = jpeg_v1_0_decode_ring_get_wptr,
> .set_wptr = jpeg_v1_0_decode_ring_set_wptr,
> diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c
> b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c
> index d0d27790b73b..099698cb1a3d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c
> @@ -1986,7 +1986,7 @@ static struct amdgpu_ring_funcs
> vcn_v4_0_unified_ring_vm_funcs = {
> .type = AMDGPU_RING_TYPE_VCN_ENC,
> .align_mask = 0x3f,
> .nop = VCN_ENC_CMD_NO_OP,
> - .extra_dw = sizeof(struct amdgpu_vcn_rb_metadata),
> + .extra_bytes = sizeof(struct amdgpu_vcn_rb_metadata),
> .get_rptr = vcn_v4_0_unified_ring_get_rptr,
> .get_wptr = vcn_v4_0_unified_ring_get_wptr,
> .set_wptr = vcn_v4_0_unified_ring_set_wptr,
