[MPCore Watchdog]: Convert from misc_dev to dynamic device node.
Wim Van Sebroeck
wim at iguana.be
Fri Jun 17 03:14:39 EDT 2011
> On Tue, Jun 14, 2011 at 05:19:06PM -0700, Peter Fordham wrote:
> > > On Tue, Jun 14, 2011 at 04:29:26PM -0700, Peter Fordham wrote:
> > >> The current MPCore watchdog driver uses a misc_dev device node.
> > >> This patch changes it to use dynamically allocated device numbers.
> > >
> > > I'm not sure that this is the correct thing to do. All other watchdog devices
> > > use a miscdevice with a major:minor of 10:130, is there a specific reason
> > > that this node needs to be dynamic?
> > I was under the impressions that dynamic device nodes were the way of the
> > future. Is that not the case?
> Well they are for new devices/subsystems but watchdog has an established
> major:minor pair that all other devices use so you don't really have to
> worry about a namespace clash.
> > I'll add the relevant checks in other places as per your suggestions.
> I've added Wim (watchdog driver maintainer), but I would think that if
> this change is worth doing then it should be done for all drivers.
> > > I believe the sysfs classes are pretty much
> > > deprecated now in preference of a bus too.
> > Can you give me some more info here? I thought the sysfs stuff was the
> > new right way of doing stuff. The class stuff allows udev to automatically
> > create the right device node.
> So here's one that I'm aware of https://lkml.org/lkml/2011/3/25/502. So
> there's nothing wrong with using sysfs and a bus, but certainly a bus is
> preferred over a class.
My opinion: we stick with the /dev/watchdog interface, we don't go for dynamic
device nodes but go for a sysfs interface. And this for all drivers and via the
new watchdog API. (updated version will be sent out today). Makes no sense
to do this for every driver.
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