[PATCH v2 1/2] drm/amdgpu: move error log from ring write to commit

[Christian König]

Am 03.10.24 um 10:28 schrieb Sunil Khatri:
> Move the error message from ring write as an optimization
> to avoid printing that message on every write instead
> print once during commit if it exceeds write the allocated
> size i.e ring->count_dw.
>
> Also we do not want to log the error message in between a
> ring write and complete the write as its mostly not harmful
> as it will overwrite stale data only as GPU read from ring
> is faster than CPU write to ring.
>
> This reduces the size of amdgpu.ko module by around
> 600 Kb as write is very often used function and hence
> the print.
>
> Signed-off-by: Sunil Khatri <sunil.khatri at amd.com>
> Suggested-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 3 +++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 2 --
>   2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> index 690976665cf6..05b3480ecec7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
> @@ -141,6 +141,9 @@ void amdgpu_ring_commit(struct amdgpu_ring *ring)
>   {
>   	uint32_t count;
>   
> +	if (ring->count_dw <= 0)
> +		DRM_ERROR("amdgpu: writing more dwords to the ring than expected!\n");
> +

Oh, I missed this on the first review a count_dw of 0 is actually ok 
since that means we have written exactly as much dw as estimated.

Regards,
Christian.

>   	/* We pad to match fetch size */
>   	count = ring->funcs->align_mask + 1 -
>   		(ring->wptr & ring->funcs->align_mask);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> index f93f51002201..af8824e8da49 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> @@ -377,8 +377,6 @@ static inline void amdgpu_ring_clear_ring(struct amdgpu_ring *ring)
>   
>   static inline void amdgpu_ring_write(struct amdgpu_ring *ring, uint32_t v)
>   {
> -	if (ring->count_dw <= 0)
> -		DRM_ERROR("amdgpu: writing more dwords to the ring than expected!\n");
>   	ring->ring[ring->wptr++ & ring->buf_mask] = v;
>   	ring->wptr &= ring->ptr_mask;
>   	ring->count_dw--;