Messages in this thread | | | From | Oliver Neukum <> | Subject | Re: [PATCH] USB: fix deadlock in HCD code | Date | Wed, 21 May 2008 15:40:24 +0200 |
| |
Am Mittwoch 21 Mai 2008 15:27:50 schrieb Jiri Kosina: > 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() -> > usb_hcd_link_urb_to_ep(). >
Sorry, yes other code paths take it with enabled interrupts. The patch is good and necessary for 2.6.26.
Regards Oliver
| |