Re: [PATCH v5 5/9] iommu/arm-smmu-v3: Refactor write_ctx_desc

[Will Deacon]

On Tue, Aug 15, 2023 at 01:04:43PM +0800, Michael Shavit wrote:
> On Thu, Aug 10, 2023 at 5:15 PM Michael Shavit <mshavit@xxxxxxxxxx> wrote:
> > On Wed, Aug 9, 2023 at 9:50 PM Will Deacon <will@xxxxxxxxxx> wrote:
> > >
> > > Since you're dropping this and relying on the lock being taken higher up
> > > callstack, can we add a lockdep assertion that we do actually hold the
> > > devices_lock, please?
> >
> > Will do!
> 
> I spoke too soon; the point of this change was to remove the
> dependency on the arm_smmu_domain, piping the devices_lock would
> defeat this. In fact, this section is really depending on the iommu
> group lock not the devices_lock.

Sorry, but I'm not following you here. What is the devices_lock protecting
if we're depending on the group lock?

Will