[lkml]   [2016]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v5 2/5] driver core: Functional dependencies tracking support
On Mon, Nov 7, 2016 at 10:22 PM, Luis R. Rodriguez <> wrote:
> 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,

It isn't particularly clear what you mean by "support" here.

I guess that you mean that it will allow the ->probe callback to be
invoked for multiple times for the same device/driver combination
without issues. If that's the case, the way the new code uses
-EPROBE_DEFER doesn't interfere with this, because it will not invoke
the ->probe callbacks for consumers at all until their (required)
suppliers are ready.

> if it does not support its not clear what will happen....

I don't see any problems here, but if you see any, please just say
what they are.

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

That's correct, but then do we need it?


 \ /
  Last update: 2016-11-10 01:43    [W:0.117 / U:0.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site