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Date:   Wed, 26 Jun 2019 10:38:57 -0400 (EDT)
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Oliver Neukum <oneukum@suse.com>
cc:     Tejun Heo <tj@kernel.org>,
        Kernel development list <linux-kernel@vger.kernel.org>,
        USB list <linux-usb@vger.kernel.org>
Subject: Re: [RFC] deadlock with flush_work() in UAS
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On Wed, 26 Jun 2019, Oliver Neukum wrote:

> Am Montag, den 24.06.2019, 10:22 -0400 schrieb Alan Stern:
> > But that pattern makes no sense; a driver would never use it.  The 
> > driver would just do the reset itself.
> 
> Correct. But UAS and storage themselves still need to use
> WQ_MEM_RECLAIM for their workqueues, don't they?

Perhaps so for uas.  usb-storage uses a work queue only for scanning 
targets, which doesn't interfere with the block I/O pathway.

Alan Stern