Re: [PATCH v2 5/5] iommu/arm-smmu: Convert to domain_alloc_paging()

[Jason Gunthorpe <jgg@nvidia.com>]

On Tue, Feb 13, 2024 at 11:16:23AM +0000, Will Deacon wrote:
> On Tue, Feb 13, 2024 at 12:55:38PM +0200, Dmitry Baryshkov wrote:
> > On Tue, 13 Feb 2024 at 12:20, Robin Murphy <robin.murphy@arm.com> wrote:
> > > On 2024-02-13 7:51 am, Dmitry Baryshkov wrote:
> > > > On Sat, 10 Feb 2024 at 00:23, Jason Gunthorpe <jgg@nvidia.com> wrote:
> > > >> And then we may get a clue from the backtraces it generates. I only
> > > >> saw one iommu group reported in your log so I'd expect one trace?
> > > >
> > > > I added dev_info + mdelays() around the arm_smmu_init_domain_context()
> > > > and I can see that it crashes within that function.
> > >
> > > Yeah, this is totally broken. We can't just call the unmodified
> > > arm_smmu_init_domain_context() at domain allocation because half of what
> > > it's doing belongs to the attach operation. We should not be allocating
> > > context banks, IRQs, etc. for a not-yet-attached domain, and we
> > > certainly shouldn't be touching hardware there outside of RPM.
> > 
> > Should I send a revert?
> 
> If reverting the patch fixes the issue for you, then yes please!

Not the whole thing though, just remove the 'if (dev)' like you
tested, thanks.

If you want I will send it

> Hopefully you can help Jason test a reworked verson for the future, as
> it's evident that Tegra doesn't tickle the power management side of things
> in the same way.

It can stay, as long as it uses the alloc_domain_paging() that is
enough for the core code to move forward.

I included it only because we were able to test it, most of the other
drivers I did not try to move their "finalize".

Jason