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

[Christian König]

Am 15.08.22 um 17:16 schrieb Felix Kuehling:
> Am 2022-08-14 um 13:27 schrieb Christian König:
>> Am 12.08.22 um 22:56 schrieb Mukul Joshi:
>>> 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.
>>
>> Mhm, the original plan was to have different ih function for the 
>> rings but I think we just forgot to implement this fully.
>>
>> When you do it this way you need to apply it to a bunch of different 
>> hw generation as Felix mentioned as well.
>>
>> Might be easier to clean that up.
>
> Right now ih_funcs cannot be different per ring. Are you suggesting 
> moving the ih_funcs into the amdgpu_ih_ring structure?

IIRC we even discussed on that already and thought that would be the 
best approach.

It's just that nobody ever came around to do it.

Regards,
Christian.

>
> Regards,
>   Felix
>
>
>>
>> Regards,
>> Christian.
>>
>>>
>>> Signed-off-by: Mukul Joshi <mukul.joshi at amd.com>
>>> ---
>>>   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;
>>