Re: [PATCH kernel v2] powerpc/iommu: Annotate nested lock for lockdep

On Mon, 1 Mar 2021 17:36:53 +1100, Alexey Kardashevskiy wrote:

The IOMMU table is divided into pools for concurrent mappings and each
pool has a separate spinlock. When taking the ownership of an IOMMU group
to pass through a device to a VM, we lock these spinlocks which triggers
a false negative warning in lockdep (below).

This fixes it by annotating the large pool's spinlock as a nest lock
which makes lockdep not complaining when locking nested locks if
the nest lock is locked already.

[...]

Applied to powerpc/next.

[1/1] powerpc/iommu: Annotate nested lock for lockdep
      https://git.kernel.org/powerpc/c/cc7130bf119add37f36238343a593b71ef6ecc1e

cheers