Re: ttydev_cdevsw has no d_purge

From: Konstantin Belousov <kostikbel_at_gmail.com>
Date: Wed, 8 Aug 2012 14:31:33 +0300
On Tue, Aug 07, 2012 at 05:03:13PM +0200, Hans Petter Selasky wrote:
> On Sunday 05 August 2012 10:33:13 Hans Petter Selasky wrote:
> > On Friday 03 August 2012 10:32:47 Ed Schouten wrote:
> > > 2012/8/1 Hans Petter Selasky <hselasky_at_c2i.net>:
> > > > I think the problem is like this, that in order to re-use the unit
> > > > numbers for USB serial tty devices, the USB stack needs to wait until a
> > > > TTY is actually freed, right? Else you will have a panic on creating
> > > > devfs entries having the same name.
> > > 
> > > Indeed. So the USB code could simply pick a different unit number.
> > 
> > Hi Ed,
> > 
> > USB could use a different Unit number. Some questions:
> > 
> > When can the previous unit number be re-used? Is there a callback for this?
> > 
> > When can the USB serial code assume that it will not be called again and
> > that all callbacks are drained?
> > 
> 
> Hi,
> 
> Can you try the attached patch and report back?

I applied the patch and reloaded ucom and uplcom. So far there were no
power glitches so UPS did not dropped off the bus yet.

I have a question regarding the changed fragment of code. Why don't you use
unr(9) KPI to manage unit numbers ?

Received on Wed Aug 08 2012 - 09:31:51 UTC

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