On Wed, 28 Oct 2020 11:27:17 -0400, Qian Cai wrote:
> Lockdep complains that a possible deadlock below in
> eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled,
> but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ
> disabled. Let's just make eeh_addr_cache_show() acquire the lock with
> IRQ disabled as well.
>
> CPU0 CPU1
> ---- ----
> lock(&pci_io_addr_cache_root.piar_lock);
> local_irq_disable();
> lock(&tp->lock);
> lock(&pci_io_addr_cache_root.piar_lock);
> <Interrupt>
> lock(&tp->lock);
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/eeh_cache: Fix a possible debugfs deadlock
https://git.kernel.org/powerpc/c/fd552e0542b4532483289cce48fdbd27b692984b
cheers
