From mboxrd@z Thu Jan  1 00:00:00 1970
From: hch@infradead.org (Christoph Hellwig)
Date: Tue, 16 Feb 2016 23:59:13 -0800
Subject: [PATCH 1/2] NVMe: Lock out shutdown during pci init
In-Reply-To: <20160216184046.GA8415@localhost.localdomain>
References: <1455231626-7166-1-git-send-email-keith.busch@intel.com>
 <20160213095851.GA15206@infradead.org>
 <20160216184046.GA8415@localhost.localdomain>
Message-ID: <20160217075913.GA14303@infradead.org>

On Tue, Feb 16, 2016@06:40:47PM +0000, Keith Busch wrote:
> On Sat, Feb 13, 2016@01:58:51AM -0800, Christoph Hellwig wrote:
> > Seems like we should be holding the lock over the call
> > to nvme_dev_disable to get protection for the whole execution,
> > e.g. by adding a __nvme_dev_disable variant that expects the lock
> > to be held.
> > 
> > Maybe it's also worth renaming shutdown_lock to register_mutex
> > or similar to better document what it protects.
> 
> Perhaps we shouldn't unmap the registers on a reset. That'd fix several
> problems, including this one and writing queue doorbells.

I always thought there was a deep reason we'd need to unmap it.  But
if there isn't getting rid of the unmap should make the driver a lot
more robust.