Re: [PATCH net v6] usbnet: fix smp_processor_id() use in preemptible context
From: Sebastian Andrzej Siewior
Date: Tue Oct 13 2026 - 05:29:14 EST
On 2026-10-13 10:54:09 [+0200], Oliver Neukum wrote:
> On 12.10.26 22:26, Alan Stern wrote:
> > Today you fix VHCI, tomorrow some other virtual HCD will cause problems.
> >
> > Should we document any requirements that all HCDs will have to follow
> > and that all completion handlers can rely on?
>
> Numerous corner cases. For example I strongly suspect that unloading
> the driver for the HC will always complete URBs synchronously.
> Please do not do this.
Sorry, I have hard time to parse this. The expectation of the USB driver
(was) that the completion handler is invoked in interrupt context.
Therefore BH is disabled one way or another.
Are you saying we should not have this behaviour documented/ expected
and assume preemptible context because "rmmod hcd" will complete all
enqueued URBs in the rmmod context?
> Regards
> Oliver
Sebastian