On Wednesday, August 15, 2012, Alan Stern wrote:
> On Tue, 14 Aug 2012, Rafael J. Wysocki wrote:
>
> >
> > If __dev_pm_qos_read_value(dev) returns a negative value,
> > rpm_suspend() should return -EPERM for dev even if its
> > power.no_callbacks flag is set. For this to happen, the device's
> > power.no_callbacks flag has to be checked after the PM QoS check,
> > so modify the code accordingly.
> >
> > Signed-off-by: Rafael J. Wysocki <r...@sisk.pl>
> > ---
> > drivers/base/power/runtime.c | 12 ++++++------
> > 1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > Index: linux/drivers/base/power/runtime.c
> > ===================================================================
> > --- linux.orig/drivers/base/power/runtime.c
> > +++ linux/drivers/base/power/runtime.c
> > @@ -388,6 +388,12 @@ static int rpm_suspend(struct device *de
> > goto repeat;
> > }
> >
> > + if (__dev_pm_qos_read_value(dev) < 0) {
> > + /* Negative PM QoS constraint means "never suspend". */
> > + retval = -EPERM;
> > + goto out;
> > + }
> > +
> > if (dev->power.no_callbacks)
> > goto no_callback; /* Assume success. */
> >
> > @@ -402,12 +408,6 @@ static int rpm_suspend(struct device *de
> > goto out;
> > }
> >
> > - if (__dev_pm_qos_read_value(dev) < 0) {
> > - /* Negative PM QoS constraint means "never suspend". */
> > - retval = -EPERM;
> > - goto out;
> > - }
> > -
> > __update_runtime_status(dev, RPM_SUSPENDING);
> >
> > if (dev->pm_domain)
>
> Wouldn't it be better to move the test into
> rpm_check_suspend_allowed()? Then it would apply to idle notifications
> and pm_schedule_suspend().
Yes, that makes sense.
Updated patch is appended.
Thanks,
Rafael
---
From: Rafael J. Wysocki <r...@sisk.pl>
Subject: PM / Runtime: Check device PM QoS setting before "no callbacks"
If __dev_pm_qos_read_value(dev) returns a negative value,
rpm_suspend() should return -EPERM for dev even if its
power.no_callbacks flag is set. For this to happen, the device's
power.no_callbacks flag has to be checked after the PM QoS check,
so move the PM QoS check to rpm_check_suspend_allowed() (this will
make it cover idle notifications as well as runtime suspend too).
Signed-off-by: Rafael J. Wysocki <r...@sisk.pl>
---
drivers/base/power/runtime.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
Index: linux/drivers/base/power/runtime.c
===================================================================
--- linux.orig/drivers/base/power/runtime.c
+++ linux/drivers/base/power/runtime.c
@@ -147,6 +147,8 @@ static int rpm_check_suspend_allowed(str
|| (dev->power.request_pending
&& dev->power.request == RPM_REQ_RESUME))
retval = -EAGAIN;
+ else if (__dev_pm_qos_read_value(dev) < 0)
+ retval = -EPERM;
else if (dev->power.runtime_status == RPM_SUSPENDED)
retval = 1;
@@ -402,12 +404,6 @@ static int rpm_suspend(struct device *de
goto out;
}
- if (__dev_pm_qos_read_value(dev) < 0) {
- /* Negative PM QoS constraint means "never suspend". */
- retval = -EPERM;
- goto out;
- }
-
__update_runtime_status(dev, RPM_SUSPENDING);
if (dev->pm_domain)
--
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