On Thursday, June 19, 2014, Rafael J. Wysocki wrote:
> On Thursday, June 19, 2014 04:23:29 PM Allen Yu wrote:
> > On Thursday, June 19, 2014, Rafael J. Wysocki wrote:
> > > On Wednesday, June 18, 2014 11:30:51 AM Alan Stern wrote:
> > > > On Tue, 17 Jun
and pm_request_resume() would still fail, but
> > pm_runtime_get() and pm_runtime_get_sync() would work? I'm not sure
> > about the reason for this distinction.
>
> The meaning of pm_runtime_get()/pm_runtime_get_sync() is "prevent the
> device from being suspended from now on and resume it if necessary" while
> "runtime PM disabled and runtime_status == RPM_ACTIVE" may be
> interpreted as "not necessary to resume", so it is reasonable to special case
> this particular situation for these particular routines IMHO.
As Rafael mentioned above that runtime_sataus is not meaningful if runtime PM
is disabled, so shouldn't we avoid using the runtime_staus here and instead use
dev->power.is_suspended only to decide the return value?
@@ -608,11 +608,13 @@ static int rpm_resume(struct device *dev, int rpmflags)
repeat:
if (dev->power.runtime_error)
retval = -EINVAL;
- else if (dev->power.disable_depth == 1 && dev->power.is_suspended
- && dev->power.runtime_status == RPM_ACTIVE)
- retval = 1;
- else if (dev->power.disable_depth > 0)
- retval = -EACCES;
+ else if (dev->power.disable_depth > 0) {
+ if (!dev->power.is_suspended)
+ retval = 1;
+ else
+ retval = -EACCES;
+ }
+
if (retval)
goto out;
However, this requires us to make sure device is in full functional state if
it's not suspended before disabling runtime PM, just like the case runtime PM
is not configured at all. And also requires device suspend routine to check
dev->power.usage_count before suspending device.
Thanks,
Allen Yu
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at all. And also requires device suspend routine to check
dev-power.usage_count before suspending device.
Thanks,
Allen Yu
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On Thursday, June 19, 2014, Rafael J. Wysocki wrote:
On Thursday, June 19, 2014 04:23:29 PM Allen Yu wrote:
On Thursday, June 19, 2014, Rafael J. Wysocki wrote:
On Wednesday, June 18, 2014 11:30:51 AM Alan Stern wrote:
On Tue, 17 Jun 2014, Rafael J. Wysocki wrote:
On Tuesday
only
allowing access to a device if it's not suspended (i.e. value of "is_suspneded"
flag is false).
> > Signed-off-by: Allen Yu
> > ---
> > drivers/base/power/runtime.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/d
state.
Whereas the case I mentioned above is before device is suspended.
It's dangerous to access device if it's in suspended state, so I propose only
allowing access to a device if it's not suspended (i.e. value of is_suspneded
flag is false).
Signed-off-by: Allen Yu all...@nvidia.com
wer transition. In this case, runtime PM status
will
be set to RPM_ACTIVE and then runtime PM is disabled. After that, device driver
may
call pm_runtime_get_sync() and rpm_resume() should return 1, because the device
is
still active as long as not been suspended.
Signed-off-by: Allen Yu
---
driv
transition. In this case, runtime PM status
will
be set to RPM_ACTIVE and then runtime PM is disabled. After that, device driver
may
call pm_runtime_get_sync() and rpm_resume() should return 1, because the device
is
still active as long as not been suspended.
Signed-off-by: Allen Yu all...@nvidia.com
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