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

From: Jason Gunthorpe <jgg@nvidia.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: Lu Baolu <baolu.lu@linux.intel.com>,
	Joerg Roedel <jroedel@suse.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Eric Auger <eric.auger@redhat.com>,
	regressions@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [REGRESSION 5.19.x] AMD HD-audio devices missing on 5.19
Date: Tue, 6 Sep 2022 12:41:51 -0300	[thread overview]
Message-ID: <YxdqP9i0bEwUg4VJ@nvidia.com> (raw)
In-Reply-To: <20220823202824.GA4516@nvidia.com>

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@8bytes.org/
> 
> 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