Re: [REGRESSION 5.19.x] AMD HD-audio devices missing on 5.19

From: Jason Gunthorpe
Date: Tue Sep 06 2022 - 12:14:58 EST


On Tue, Aug 23, 2022 at 05:28:24PM -0300, Jason Gunthorpe wrote:
> On Tue, Aug 23, 2022 at 01:46:36PM +0200, Takashi Iwai wrote:
> > It was tested now and confirmed that the call path is via AMDGPU, as
> > expected:
> > amdgpu_pci_probe ->
> > amdgpu_driver_load_kms ->
> > amdgpu_device_init ->
> > amdgpu_amdkfd_device_init ->
> > kgd2kfd_device_init ->
> > kgd2kfd_resume_iommu ->
> > kfd_iommu_resume ->
> > amd_iommu_init_device ->
> > iommu_attach_group ->
> > __iommu_attach_group
>
> Oh, when you said sound intel I thought this was an Intel CPU..
>
> Yes, there is this hacky private path from the amdgpu to
> the amd iommu driver that makes a mess of it here. We discussed it in
> this thread:
>
> https://lore.kernel.org/linux-iommu/YgtuJQhY8SNlv9%2F6@xxxxxxxxxx/
>
> But nobody put it together that it would be a problem with this.
>
> Something like this, perhaps, but I didn't check if overriding the
> type would cause other problems.

Takashi, do we want to do this patch?

Thanks,
Jason