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

[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?

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;
>