[PATCH] drm/amdgpu: Fix interrupt handling on ih_soft ring

[Felix Kuehling]

On 2022-08-12 16:56, Mukul Joshi wrote:
> There are no backing hardware registers for ih_soft ring.
> As a result, don't try to access hardware registers for read
> and write pointers when processing interrupts on the IH soft
> ring.
>
> Signed-off-by: Mukul Joshi <mukul.joshi at amd.com>

The patch looks good to me. But you probably should apply the same 
changes to vega10_ih.c and navi10_ih.c as well.

Regards,
   Felix


> ---
>   drivers/gpu/drm/amd/amdgpu/vega20_ih.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/vega20_ih.c b/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
> index 3b4eb8285943..2022ffbb8dba 100644
> --- a/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
> +++ b/drivers/gpu/drm/amd/amdgpu/vega20_ih.c
> @@ -385,9 +385,11 @@ static u32 vega20_ih_get_wptr(struct amdgpu_device *adev,
>   	u32 wptr, tmp;
>   	struct amdgpu_ih_regs *ih_regs;
>   
> -	if (ih == &adev->irq.ih) {
> +	if (ih == &adev->irq.ih || ih == &adev->irq.ih_soft) {
>   		/* Only ring0 supports writeback. On other rings fall back
>   		 * to register-based code with overflow checking below.
> +		 * ih_soft ring doesn't have any backing hardware registers,
> +		 * update wptr and return.
>   		 */
>   		wptr = le32_to_cpu(*ih->wptr_cpu);
>   
> @@ -461,6 +463,9 @@ static void vega20_ih_set_rptr(struct amdgpu_device *adev,
>   {
>   	struct amdgpu_ih_regs *ih_regs;
>   
> +	if (ih == &adev->irq.ih_soft)
> +		return;
> +
>   	if (ih->use_doorbell) {
>   		/* XXX check if swapping is necessary on BE */
>   		*ih->rptr_cpu = ih->rptr;