Re: [Ksummit-discuss] Schedule slot suggestion- Generic drivers - core topic

[Greg KH <greg@kroah.com>]

On Fri, Oct 28, 2016 at 02:38:13PM -0700, Dmitry Torokhov wrote:
> On Fri, Oct 28, 2016 at 2:29 PM, Jiri Kosina <jikos@kernel.org> wrote:
> > On Fri, 28 Oct 2016, Greg KH wrote:
> >
> >> On Fri, Oct 28, 2016 at 02:16:59PM -0700, Luis R. Rodriguez wrote:
> >> > Having some generic device driver load, prior to a specific driver,
> >> > and issues / maintenance issues that come with the hacks currently in
> >> > place to support this / re-invent the wheel to support this per
> >> > subsystem.
> >>
> >> We have hacks for this today?  What do you mean by this, quirks?
> >
> > I have to maintain a device-id list that explicitly enumerates "these
> > devices can be handled by generic driver, but would better be handled by
> > specific driver", in the generic driver itself. Which is horrible.
> >
> > It'd be nice for the specific driver to be able to claim this property
> > somehow.
> 
> Now that most of the environment is ready to handle hotplug, for HID
> it should be doable: have hid-generic probe devices last and have
> driver core recognize generic/vs tailored driver (flag?) and if device
> matches tailored driver forcibly unbind from generic and allow
> tailored to bind to the device. There will be window of time when
> device is bound to a "wrong" driver, but because of hotplug who cares.

"forcibly unbind" is the trick here, along with the fact of drivers not
being asked to match with devices already bound to a driver.  It might
be possible, I'd love to see patches to try it, given that the topic
comes up every other year or so...

thanks,

greg k-h