* Runtime PM status sysfs attribute
@ 2010-07-01 17:16 Alan Stern
2010-07-01 18:54 ` Dominik Brodowski
2010-07-02 5:34 ` Oliver Neukum
0 siblings, 2 replies; 6+ messages in thread
From: Alan Stern @ 2010-07-01 17:16 UTC (permalink / raw)
To: Dominik Brodowski; +Cc: Linux-pm mailing list
Dominik:
As runtime PM becomes more and more popular, it seems likely that
people will want to know whether or not their devices are getting
suspended. Or if not people, then programs like powertop.
For that reason, it seems to make sense to build the runtime_status
sysfs attribute even when CONFIG_PM_ADVANCED_DEBUG isn't enabled. Do
you agree?
Alan Stern
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Runtime PM status sysfs attribute
2010-07-01 17:16 Runtime PM status sysfs attribute Alan Stern
@ 2010-07-01 18:54 ` Dominik Brodowski
2010-07-01 20:23 ` Alan Stern
2010-07-02 5:34 ` Oliver Neukum
1 sibling, 1 reply; 6+ messages in thread
From: Dominik Brodowski @ 2010-07-01 18:54 UTC (permalink / raw)
To: Alan Stern; +Cc: Linux-pm mailing list
Alan,
On Thu, Jul 01, 2010 at 01:16:31PM -0400, Alan Stern wrote:
> As runtime PM becomes more and more popular, it seems likely that
> people will want to know whether or not their devices are getting
> suspended. Or if not people, then programs like powertop.
>
> For that reason, it seems to make sense to build the runtime_status
> sysfs attribute even when CONFIG_PM_ADVANCED_DEBUG isn't enabled. Do
> you agree?
good idea; haven't looked at any dependencies yet, though...
Best,
Dominik
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Runtime PM status sysfs attribute
2010-07-01 18:54 ` Dominik Brodowski
@ 2010-07-01 20:23 ` Alan Stern
2010-07-01 21:13 ` Rafael J. Wysocki
0 siblings, 1 reply; 6+ messages in thread
From: Alan Stern @ 2010-07-01 20:23 UTC (permalink / raw)
To: Dominik Brodowski; +Cc: Linux-pm mailing list
On Thu, 1 Jul 2010, Dominik Brodowski wrote:
> Alan,
>
> On Thu, Jul 01, 2010 at 01:16:31PM -0400, Alan Stern wrote:
> > As runtime PM becomes more and more popular, it seems likely that
> > people will want to know whether or not their devices are getting
> > suspended. Or if not people, then programs like powertop.
> >
> > For that reason, it seems to make sense to build the runtime_status
> > sysfs attribute even when CONFIG_PM_ADVANCED_DEBUG isn't enabled. Do
> > you agree?
>
> good idea; haven't looked at any dependencies yet, though...
Reading through the code shows there is a drawback: For subsystems that
don't implement runtime PM, devices will always show up as "suspended".
That's not going to be very useful, unfortunately.
Still, for subsystems that _do_ implement runtime PM, there doesn't
seem to be any other way to learn the current status of a device.
Alan Stern
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Runtime PM status sysfs attribute
2010-07-01 20:23 ` Alan Stern
@ 2010-07-01 21:13 ` Rafael J. Wysocki
2010-07-01 23:16 ` Alan Stern
0 siblings, 1 reply; 6+ messages in thread
From: Rafael J. Wysocki @ 2010-07-01 21:13 UTC (permalink / raw)
To: linux-pm; +Cc: Dominik Brodowski
On Thursday, July 01, 2010, Alan Stern wrote:
> On Thu, 1 Jul 2010, Dominik Brodowski wrote:
>
> > Alan,
> >
> > On Thu, Jul 01, 2010 at 01:16:31PM -0400, Alan Stern wrote:
> > > As runtime PM becomes more and more popular, it seems likely that
> > > people will want to know whether or not their devices are getting
> > > suspended. Or if not people, then programs like powertop.
> > >
> > > For that reason, it seems to make sense to build the runtime_status
> > > sysfs attribute even when CONFIG_PM_ADVANCED_DEBUG isn't enabled. Do
> > > you agree?
> >
> > good idea; haven't looked at any dependencies yet, though...
>
> Reading through the code shows there is a drawback: For subsystems that
> don't implement runtime PM, devices will always show up as "suspended".
> That's not going to be very useful, unfortunately.
>
> Still, for subsystems that _do_ implement runtime PM, there doesn't
> seem to be any other way to learn the current status of a device.
Perhaps we can rework the attribute to show "unknown" for devices that
have power.disable_depth > 0 ?
Rafael
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Runtime PM status sysfs attribute
2010-07-01 21:13 ` Rafael J. Wysocki
@ 2010-07-01 23:16 ` Alan Stern
0 siblings, 0 replies; 6+ messages in thread
From: Alan Stern @ 2010-07-01 23:16 UTC (permalink / raw)
To: Rafael J. Wysocki; +Cc: linux-pm, Dominik Brodowski
On Thu, 1 Jul 2010, Rafael J. Wysocki wrote:
> On Thursday, July 01, 2010, Alan Stern wrote:
> > On Thu, 1 Jul 2010, Dominik Brodowski wrote:
> >
> > > Alan,
> > >
> > > On Thu, Jul 01, 2010 at 01:16:31PM -0400, Alan Stern wrote:
> > > > As runtime PM becomes more and more popular, it seems likely that
> > > > people will want to know whether or not their devices are getting
> > > > suspended. Or if not people, then programs like powertop.
> > > >
> > > > For that reason, it seems to make sense to build the runtime_status
> > > > sysfs attribute even when CONFIG_PM_ADVANCED_DEBUG isn't enabled. Do
> > > > you agree?
> > >
> > > good idea; haven't looked at any dependencies yet, though...
> >
> > Reading through the code shows there is a drawback: For subsystems that
> > don't implement runtime PM, devices will always show up as "suspended".
> > That's not going to be very useful, unfortunately.
> >
> > Still, for subsystems that _do_ implement runtime PM, there doesn't
> > seem to be any other way to learn the current status of a device.
>
> Perhaps we can rework the attribute to show "unknown" for devices that
> have power.disable_depth > 0 ?
That sounds reasonable. "disabled" is another possibility, but it
doesn't express the right idea: The _status_ isn't what's disabled.
Alan Stern
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Runtime PM status sysfs attribute
2010-07-01 17:16 Runtime PM status sysfs attribute Alan Stern
2010-07-01 18:54 ` Dominik Brodowski
@ 2010-07-02 5:34 ` Oliver Neukum
1 sibling, 0 replies; 6+ messages in thread
From: Oliver Neukum @ 2010-07-02 5:34 UTC (permalink / raw)
To: linux-pm; +Cc: Dominik Brodowski
Am Donnerstag, 1. Juli 2010, 19:16:31 schrieb Alan Stern:
> Dominik:
>
> As runtime PM becomes more and more popular, it seems likely that
> people will want to know whether or not their devices are getting
> suspended. Or if not people, then programs like powertop.
>
> For that reason, it seems to make sense to build the runtime_status
> sysfs attribute even when CONFIG_PM_ADVANCED_DEBUG isn't enabled. Do
> you agree?
For what it's worth, I think this is a good idea.
Regards
Oliver
^ permalink raw reply [flat|nested] 6+ messages in thread
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2010-07-01 17:16 Runtime PM status sysfs attribute Alan Stern
2010-07-01 18:54 ` Dominik Brodowski
2010-07-01 20:23 ` Alan Stern
2010-07-01 21:13 ` Rafael J. Wysocki
2010-07-01 23:16 ` Alan Stern
2010-07-02 5:34 ` Oliver Neukum
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