Re: [REGRESSION] "bind" a device to a driver doesn't not workanymore

From: Greg KH
Date: Mon Oct 26 2009 - 20:02:15 EST


On Mon, Oct 26, 2009 at 02:34:50PM -0700, Dmitry Torokhov wrote:
> On Mon, Oct 26, 2009 at 01:59:53PM -0700, Greg KH wrote:
> > On Thu, Oct 22, 2009 at 07:01:50PM -0700, Dmitry Torokhov wrote:
> > > On Sun, Oct 18, 2009 at 01:02:38AM -0700, Greg KH wrote:
> > > > On Sun, Oct 18, 2009 at 12:51:27AM -0700, Dmitry Torokhov wrote:
> > > > > On Mon, Oct 12, 2009 at 08:17:41PM -0700, Dmitry Torokhov wrote:
> > > > > > On Mon, Oct 12, 2009 at 11:54:17AM -0700, Greg KH wrote:
> > > > > > > On Mon, Oct 12, 2009 at 11:33:13AM -0700, Dmitry Torokhov wrote:
> > > > > > > > On Mon, Oct 12, 2009 at 10:35:51AM -0700, Greg KH wrote:
> > > > > > > > > On Mon, Oct 12, 2009 at 08:48:46AM -0700, Dmitry Torokhov wrote:
> > > > > > > > > > > So at least, unbind should fail as well as bind.
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > That would be Greg's domain s it is driver core decision whether to
> > > > > > > > > > allow unbinding platform devices registered with
> > > > > > > > > > platform_driver_probe().
> > > > > > > > >
> > > > > > > > > No, I do not see why that should not be allowed.
> > > > > > > > >
> > > > > > > >
> > > > > > > > Because once you did unbind the device you are stuck (unless the driver
> > > > > > > > is compiled as a module, but then you could just unload the module
> > > > > > > > instead of unbinding). Disallowing unbind would allow discarding not
> > > > > > > > only __devinit but __devexit sections when driver is built in which
> > > > > > > > would make ebedded people happy[^Hier].
> > > > > > >
> > > > > > > Yeah, good point.
> > > > > > >
> > > > > > > Does anyone do bind/unbind with platform devices today?
> > > > > > >
> > > > > > > If not, a patch changing this would be welcome.
> > > > > > >
> > > > > >
> > > > > > How about this one?
> > > > > >
> > > > >
> > > > > *ping* We need to resolve this, otherwise everyone who likes to rebind
> > > > > i8042 in couse of STR/STD will be in trouble.
> > > >
> > > > Sorry, am in Tokyo right now.
> > > >
> > > > I like this patch, and will queue it up, but it's too late for .32, it
> > > > will have to wait for .33.
> > > >
> > >
> > > Greg,
> > >
> > > I hope you will reconsider. The patch is extremely small but without it
> > > I am afraid many people whose distributions blindly rebind i8042 on
> > > suspend/resume will lose their keyboards and mice now that i8042 uses
> > > platform_driver_probe()...
> >
> > What distros do something like that automatically?
>
> It looks SUSE recommends to do so in one of the Wikis.. There certainly
> lots of recommendations to do so in case of keyboard resume troubles all
> over the forums (Ubunto, Gentoo, other random ones).
>
> > And this patch will
> > not solve that problem, just forbid it from happening, right?
> >
>
> It will prevent unbind from happening so that users who have suspend and
> resume working properly but who have bind/unbind in their suspend/resume
> scripts regardless will not run into trouble.
>
> This still leaves users whose suspend/resume don't work by default but I
> would rather fix their boxes properly instead of relying on that
> workaround.

Ok, fair enough, I'll queue it up for .32.

thanks,

greg k-h
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