Re: [RFC v1 0/3] driver-core: add asynch module loading support

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Sun, Aug 31, 2014 at 12:26:06PM -0700, Arjan van de Ven wrote:
> On 8/31/2014 10:52 AM, Dmitry Torokhov wrote:
> >On Sun, Aug 31, 2014 at 07:05:26AM -0400, Tejun Heo wrote:
> >>On Sun, Aug 31, 2014 at 07:02:00AM -0400, Tejun Heo wrote:
> >>>So, something like the following.  A couple things to note
> >>>
> >>>* driver_attach() can never fail but is marked with __must_check.  We
> >>>   prolly should change it to void.
> >>>
> >>>* Old/weird userspace which depends on insmod to wait for device
> >>>   probing might choke and the new behavior might need to be switched
> >>>   somehow (sysctl, insmod param or whatever).
> >>
> >>One more thing.
> >>
> >>* Use of ordered workqueue probably isn't necessary and using
> >>   system_unbound_wq should be fine.
> >>
> >
> >For my use case (touchpad taking long time to initialize) I explicitly do not
> >want it to keep order of initialization. I want to make sure the rest of the
> >kernel continues initialization while touchpad device resets.
> 
> but we do that right now
> 
> you know its there synchronous
> and do the heavy stuff async

No, in general we do not. I have hacked in serio (i.e. PS/2 support to do
registration/probing in a separate thread - and I'd love to drop that code),
but PS/2 is in its way out and we need the same for devices on I2C. SPI and
other slow buses.

Thanks.

-- 
Dmitry