From mboxrd@z Thu Jan  1 00:00:00 1970
From: jgunthorpe@obsidianresearch.com (Jason Gunthorpe)
Date: Mon, 20 Apr 2015 09:56:48 -0600
Subject: [tpmdd-devel] [RFC PATCH 1/2] tee: generic TEE subsystem
In-Reply-To: <20150420145432.GD7261@kroah.com>
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 <20150417163054.GA28241@obsidianresearch.com>
 <20150418090147.GF12732@n2100.arm.linux.org.uk>
 <20150418172923.GA10605@obsidianresearch.com>
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 <20150420050800.GA12928@obsidianresearch.com>
 <20150420145432.GD7261@kroah.com>
Message-ID: <20150420155648.GA7676@obsidianresearch.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Apr 20, 2015 at 04:54:32PM +0200, Greg Kroah-Hartman wrote:
> On Sun, Apr 19, 2015 at 11:08:00PM -0600, Jason Gunthorpe wrote:
> > I still suspect the expected way to write a new mid layer is to create
> > your own struct device and not rely on misc_device,
> 
> Yes, that is the way.  You can not use misc_device for anything other
> than creating the char node that your driver can use through the fileops
> you pass to it.
> 
> Do not use a misc_device to create sysfs files for, or anything else, it
> will be wrong and racy, as you have pointed out.

Thanks!

Can you quickly comment on when a misc device should be used compared to
alloc_chrdev_region & cdev_add ?

Jason