Re: [lkp] [PM / sleep] 013c074f86: [drm:intel_opregion_init [i915]] *ERROR* No ACPI video bus found
From: Dmitry Torokhov
Date: Tue Jan 12 2016 - 15:25:22 EST
On Tue, Jan 12, 2016 at 09:11:15PM +0100, Rafael J. Wysocki wrote:
> On Tuesday, January 12, 2016 08:38:57 PM Grygorii Strashko wrote:
> > Hi All,
> > Cc: more people + linux-input@xxxxxxxxxxxxxxx
> > On 01/07/2016 03:49 AM, kernel test robot wrote:
> > > FYI, we noticed the below changes on
> > >
> > > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > commit 013c074f8642d8e815ad670601f8e27155a74b57 ("PM / sleep: prohibit devices probing during suspend/hibernation")
> > >
> > > <4>[ 33.021805] serio serio0: device_attach() failed for isa0060/serio0 (i8042 KBD port), error: -517
> > > <4>[ 33.021813] serio serio1: device_attach() failed for isa0060/serio1 (i8042 AUX port), error: -517
> > > <6>[ 33.021906] PM: resume of devices complete after 171.688 msecs
> > >
> > > To reproduce:
> > >
> > > git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
> > > cd lkp-tests
> > > bin/lkp install job.yaml # job file is attached in this email
> > > bin/lkp run job.yaml
> > I've done some investigation of the above log output:
> > 1) Small introduction first: commit 013c074f8642 was created, because it was identified
> > that it's unsafe to bind/probe drivers during suspend resume, mainly because this will
> > cause changing of pointers on PM data structures on the fly for devices which already
> > tracked by Suspend core.
> > 2) above log prints can be generated by the below call chain (I've checked the code only):
> > drivers/input/serio/serio.c
> > serio_resume()
> > - serio_queue_event(serio, NULL, SERIO_RECONNECT_PORT)
> > - queue_work(system_long_wq, &serio_event_work);
> > ....
> > - serio_handle_event()
> > - serio_reconnect_port()
> > - serio_reconnect_driver() --- return <0
Any chance you could track why serio_reconnect_driver returns error
here? Ideally it should have succeeded.
> > - serio_disconnect_port()
> > - device_release_driver() --- unbind
> > - serio_find_driver()
> > error = device_attach(&serio->dev);
> > if (error < 0)
> > dev_warn(&serio->dev,
> > "device_attach() failed for %s (%s), error: %d\n",
> > serio->phys, serio->name, error);
> > device_attach() will return -EPROBE_DEFER(-517) because the device probing is not allowed yet.
> > As per my understanding (and it's not clear from issue description), above situation
> > should not break functionality of the system - just device's probe will be delayed till the
> > end of dpm_complete(). So, I propose consider the option - do not print above warnings if
> > return code from device_attach() is -EPROBE_DEFER.
> This looks like a reasonable thing to do to me.
Looks like it will work.