From: Peter Chen <hzpeterchen@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>,
florian@mickler.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org,
usb-storage@lists.one-eyed-alien.net
Subject: Re: Freezable workqueue blocks non-freezable workqueue during the system resume process
Date: Fri, 26 Feb 2016 14:19:20 +0800 [thread overview]
Message-ID: <20160226061920.GA17288@shlinux2.ap.freescale.net> (raw)
In-Reply-To: <20160225220112.GM6092@mtj.duckdns.org>
On Thu, Feb 25, 2016 at 05:01:12PM -0500, Tejun Heo wrote:
> Hello, Peter.
>
> On Wed, Feb 24, 2016 at 03:24:30PM +0800, Peter Chen wrote:
> > > You might want to complain to the block-layer people about this. I
> > > don't know if anything can be done to fix it.
> > >
> > > Or maybe flush_work and flush_delayed_work can be changed to avoid
> > > blocking if the workqueue is frozen. Tejun?
> > >
> >
> > I have a patch to show the root cause of this issue.
> >
> > http://www.spinics.net/lists/linux-usb/msg136815.html
>
> I don't get it. Why would it deadlock? Shouldn't things get rolling
> once the workqueues are thawed?
>
Hi Tejun,
The workqueue writeback can't be thawed due to driver's resume
(dpm_complete) is lock nested, and can't be finished.
--
Best Regards,
Peter Chen
next prev parent reply other threads:[~2016-02-26 6:23 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-23 3:20 Freezable workqueue blocks non-freezable workqueue during the system resume process Peter Chen
2016-02-23 9:47 ` Peter Chen
2016-02-23 15:34 ` Alan Stern
2016-02-24 7:24 ` Peter Chen
2016-02-25 22:01 ` Tejun Heo
2016-02-26 6:19 ` Peter Chen [this message]
2016-03-02 16:00 ` Tejun Heo
2016-03-03 9:33 ` Jan Kara
2016-03-11 17:56 ` Tejun Heo
2016-03-14 7:22 ` Jan Kara
2016-03-14 14:37 ` Alan Stern
2016-03-15 9:25 ` Jan Kara
2016-03-16 15:00 ` Tejun Heo
2016-03-16 15:37 ` Should suspend plug low-level devices? Alan Stern
2016-03-16 16:31 ` Rafael J. Wysocki
2016-03-16 16:35 ` Tejun Heo
2016-03-16 16:39 ` Rafael J. Wysocki
2016-03-16 23:18 ` Jiri Kosina
2016-03-16 23:24 ` Rafael J. Wysocki
2016-03-16 23:42 ` Jiri Kosina
2016-03-16 23:48 ` Rafael J. Wysocki
2016-03-17 7:50 ` Oliver Neukum
2016-03-17 8:02 ` Jiri Kosina
2016-03-17 8:20 ` Oliver Neukum
2016-03-17 8:35 ` Jiri Kosina
2016-03-17 9:12 ` Oliver Neukum
2016-03-17 10:20 ` Jiri Kosina
2016-03-17 10:29 ` Oliver Neukum
2016-03-17 10:36 ` Jiri Kosina
2016-03-17 18:55 ` Alan Stern
2016-03-18 20:29 ` Tejun Heo
2016-03-17 0:05 ` Tejun Heo
2016-03-17 18:58 ` Alan Stern
2016-03-18 20:25 ` Tejun Heo
2016-03-17 18:53 ` Alan Stern
2016-03-18 20:29 ` Tejun Heo
2016-03-16 16:34 ` Tejun Heo
2016-03-17 18:51 ` Alan Stern
2016-03-18 20:32 ` Tejun Heo
2016-03-18 21:06 ` Alan Stern
2016-03-20 18:29 ` Tejun Heo
2016-03-21 14:38 ` Alan Stern
2016-03-30 17:09 ` Tejun Heo
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