Re: [PATCH] USB: fix deadlock in HCD code

From: Jiri Kosina
Date: Wed May 21 2008 - 09:28:06 EST

On Wed, 21 May 2008, Oliver Neukum wrote:

> > hcd_urb_list_lock is used for synchronization between IRQ and non-IRQ
> > contexts, so the non-IRQ context has to disable IRQs in order to prevent
> > deadlocking with IRQ context.
> Which non-irq context is that?

One example -- assume usb_submit_urb() called from non-IRQ context. Then

usb_hcd_submit_urb() -> rh_urb_enqueue() -> rh_queue_status() ->

Jiri Kosina
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