Re: [PATCH v5 2/5] driver core: Functional dependencies tracking support

From: Luis R. Rodriguez
Date: Mon Nov 07 2016 - 16:22:56 EST


On Thu, Oct 27, 2016 at 05:25:51PM +0200, Greg Kroah-Hartman wrote:
> On Wed, Oct 26, 2016 at 01:19:02PM +0200, Lukas Wunner wrote:
> > Hi Rafael,
> >
> > sorry for not responding to v5 of your series earlier, just sending
> > this out now in the hope that it reaches you before your travels.
> >
> > On Mon, Oct 10, 2016 at 02:51:04PM +0200, Rafael J. Wysocki wrote:
> > > - Modify device_links_check_suppliers(), device_links_driver_bound(),
> > > device_links_no_driver(), device_links_driver_cleanup(), device_links_busy(),
> > > and device_links_unbind_consumers() to walk link lists under device_links_lock
> > > (to make the new "driver presence tracking" mechanism work reliably).
> >
> > This change might increase boot time if drivers return -EPROBE_DEFER.
>
> "might"? Please verify this before guessing....
>
> And don't make this more complex than needed before actually determining
> a real issue.

As clarified by Rafael at Plumbers, this functional dependencies
framework assumes your driver / subsystem supports deferred probe,
if it does not support its not clear what will happen....

We have no explicit semantics to check if a driver / subsystem
supports deferred probe.

Luis