lkml.org 
[lkml]   [2008]   [May]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH] USB: fix deadlock in HCD code
Date
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



\
 
 \ /
  Last update: 2008-05-21 15:43    [W:0.040 / U:1.232 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site