Re: [PATCH net 4/4] eth: bnxt: avoid deadlock when canceling IRQ affinity notifier

On Mon, Aug 3, 2026 at 12:31 PM Jakub Kicinski <[email protected]> wrote:
>
> Unregistering IRQ affinity notifiers waits for the callback synchronously.
> bnxt takes the netdev instance lock in the notifier (to restart the queue)
> and cancels the work under the same lock. This may obviously deadlock.
>
> Move the restart to the async service task. The queue restart isn't
> super time sensitive. Store the new TPH tag, schedule the task.
> Safely canceling the service task is already ironed out.
>
> In bnxt_request_irq() the order of registering notifier, affinity and
> initial TPH programming has to be inverted. I think it was racy
> previously since user may trigger an update as soon as notifier
> is installed.
>
> There's a small known gap - if pcie_tph_get_cpu_st() fails at init
> and the target tag is 0 we may miss programming the entry.
> This does not seem worth fixing, the code has skip-on-failure
> all over the place, anyway.
>
> Fixes: c214410c47d6 ("bnxt_en: Add TPH support in BNXT driver")
> Signed-off-by: Jakub Kicinski <[email protected]>

Thanks for the patches.  We'll get the patches tested in our lab.