From: Oliver Neukum <oliver@neukum.org>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Greg KH <greg@kroah.com>,
linux-usb@vger.kernel.org, Alan Stern <stern@rowland.harvard.edu>,
lchiquitto@novell.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] USB: fix deadlock in HCD code
Date: Wed, 21 May 2008 15:40:24 +0200 [thread overview]
Message-ID: <200805211540.25135.oliver@neukum.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0805211524130.6718@jikos.suse.cz>
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
next prev parent reply other threads:[~2008-05-21 13:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-21 12:09 [PATCH] USB: fix deadlock in HCD code Jiri Kosina
2008-05-21 13:21 ` Oliver Neukum
2008-05-21 13:27 ` Jiri Kosina
2008-05-21 13:32 ` Oliver Neukum
2008-05-21 13:36 ` Jiri Kosina
2008-05-21 13:47 ` Oliver Neukum
2008-05-21 14:13 ` Alan Stern
2008-05-21 14:22 ` Jiri Kosina
2008-05-21 14:46 ` Alan Stern
2008-05-21 19:32 ` Leonardo Chiquitto
2008-05-21 20:03 ` Oliver Neukum
2008-05-21 14:29 ` David Vrabel
2008-05-21 14:42 ` Alan Stern
2008-05-21 14:53 ` David Vrabel
2008-05-21 14:58 ` Alan Stern
2008-05-21 14:31 ` Oliver Neukum
2008-05-21 13:40 ` Oliver Neukum [this message]
2008-05-21 22:26 ` Peter Zijlstra
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