Re: [PATCH 5/8] drm/amdgpu/sdma: Clear SDMA rings after reset before starting them

["Lazar, Lijo" <lijo.lazar@amd.com>]

On 04-Sep-26 12:58 PM, Timur Kristóf wrote:
> The ring contains commands that were emitted before the reset.
> These need to be cleared to make sure the HW doesn't execute
> them, because they are garbage at this point.
> 
> Note that the ring reset helpers will re-emit the commands
> that are necessary after the reset.
> 
> Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> index fbac732f3e01..66f278f77f71 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c
> @@ -593,6 +593,18 @@ int amdgpu_sdma_reset_engine(struct amdgpu_device *adev, uint32_t instance_id,
>   		goto exit;
>   	}
>   
> +	amdgpu_ring_clear_ring(gfx_ring);
> +	gfx_ring->wptr = 0;
> +	atomic64_set((atomic64_t *)gfx_ring->wptr_cpu_addr, 0);
> +	atomic64_set((atomic64_t *)gfx_ring->rptr_cpu_addr, 0);
> +
> +	if (adev->sdma.has_page_queue) {
> +		amdgpu_ring_clear_ring(page_ring);
> +		page_ring->wptr = 0;
> +		atomic64_set((atomic64_t *)page_ring->wptr_cpu_addr, 0);
> +		atomic64_set((atomic64_t *)page_ring->rptr_cpu_addr, 0);
> +	}

This could be made as a small inline function like 
amdgpu_ring_reset_ptr(ring);

Thanks,
Lijo

> +
>   	if (sdma_instance->funcs->start_kernel_queue) {
>   		sdma_instance->funcs->start_kernel_queue(gfx_ring);
>   		if (adev->sdma.has_page_queue)