Re: [git pull] Input updates for 3.5-rc0

Dmitry Torokhov
2012-05-24T21:57:04Z

On Thu, May 24, 2012 at 02:44:31PM -0700, Linus Torvalds wrote:
> On Thu, May 24, 2012 at 2:07 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> > On Thu, May 24, 2012 at 1:59 PM, Dmitry Torokhov
> > <dmitry.torokhov@gmail.com> wrote:
> >>
> >> I was concerned about the _next_ device (the one that will be created
> >> the moment I plug in the tablet back into the same port) having exact
> >> same name as the one that is half dead and clashing in sysfs and
> >> elsewhere. We used to have issues with this.
> >
> > Ok, that's certainly a valid concern.
> >
> > It's still - I think - really sad/wrong that the device name is then
> > so useless than the drivers end up basically not using it.
>
> Ok, so I wonder if we could solve the issue at least partly by
> separating the "print name for kernel messages" from the "name used
> for /sysfs etc".
>
> Because you're right: the sysfs uniqueness rules does make it very
> hard to do a good job on descriptive names.
>
> Also, in sysfs, you by definition see the parent (hey, it's part of
> the path), so in sysfs, duplicating parent data would be useless and
> just ugly.
>
> But for dev_dbg(), those sysfs rules actually act against us: the name
> of a device is often tied to the parent bus location.
>
> So I wonder if we could teach dev_printk() to use something more
> interesting than "dev_name()" when appropriate? Greg?

Maybe we could traverse up the tree till we find first non-class device
(i.e. device with real driver bound to it)? Then we'd have:

wacom 2-1.2:1.0/inputX/eventY: some error happened

type of messages...

--
Dmitry