Re: arm qemu boot failures in -next due to 'PM / Domains: add setter for dev.pm_domain'

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Monday, January 11, 2016 12:04:50 PM Guenter Roeck wrote:
> On Mon, Jan 11, 2016 at 10:55:00AM -0800, Tony Lindgren wrote:
> > * Guenter Roeck <linux@roeck-us.net> [160111 09:51]:
> > > Hi,
> > > 
> > > I see 6 out of 24 arm qemu tests failing in next-20160111. Bisect points
> > > to commit 989561de9b51 ("PM / Domains: add setter for dev.pm_domain").
> > > Failures are silent - there is no output on the console.
> > > Affected tests are
> > > 
> > > arm:beagle:multi_v7_defconfig:omap3-beagle
> > > arm:beaglexm:multi_v7_defconfig:omap3-beagle-xm
> > > arm:overo:multi_v7_defconfig:omap3-overo-tobi
> > > arm:beagle:omap2plus_defconfig:omap3-beagle
> > > arm:beaglexm:omap2plus_defconfig:omap3-beagle-xm
> > > arm:overo:omap2plus_defconfig:omap3-overo-tobi
> > > 
> > > For details please see the 'next' column at http://server.roeck-us.net:8010/builders.
> > > 
> > > Reverting the offending commit fixes the problems.
> > > 
> > > Please let me know if there is anything I can do to help tracking down the problem.
> > 
> > The following fixes the booting, but I wonder if it's a
> 
> Yes, it does. 
> 
> Tested-by: Guenter Roeck <linux@roeck-us.net>
> 
> > proper fix?
> > 
> That I don't know.

If I'm not mistaken, what happens is that device_is_bound() tries to
dereference dev->p which is NULL.  If that's the case, the appended one
should help too.

Can you please check?

---
 drivers/base/dd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-pm/drivers/base/dd.c
===================================================================
--- linux-pm.orig/drivers/base/dd.c
+++ linux-pm/drivers/base/dd.c
@@ -234,7 +234,7 @@ late_initcall(deferred_probe_initcall);
  */
 bool device_is_bound(struct device *dev)
 {
-	return klist_node_attached(&dev->p->knode_driver);
+	return dev->p && klist_node_attached(&dev->p->knode_driver);
 }
 
 static void driver_bound(struct device *dev)