From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamie@jamieiles.com (Jamie Iles) Date: Wed, 15 Jun 2011 09:58:20 +0100 Subject: [MPCore Watchdog]: Convert from misc_dev to dynamic device node. In-Reply-To: References: <20110614234858.GA15534@gallagher> Message-ID: <20110615085820.GH3075@pulham.picochip.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Jamie