[RFC PATCH 0/4] USB: HCD/EHCI: giveback of URB in tasklet context

[Oliver Neukum]

On Wednesday 12 June 2013 10:35:44 Alan Stern wrote:
> On Wed, 12 Jun 2013, Ming Lei wrote:
> 
> > If not, I am wondering why one USB driver need register another hard
> > interrupt handler? Could you share such examples? I understand the
> > case only exists with timer handler as discussed with Oliver, don't I?
> 
> Here's another possibility.  A USB driver has a private lock, and it
> acquires this lock in its completion handler.  But it also acquires
> this lock in other routines, and those other routines may be called by
> other drivers or subsystems in interrupt context.

That is fatal. But again mechanically using _irqsave in complete()
does the job. No other place can be affected.

	Regards
		Oliver