[ 178/262] PM / Runtime: Check device PM QoS setting before "no callbacks" check

From: Greg Kroah-Hartman
Date: Fri Sep 28 2012 - 15:25:21 EST


From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.5-stable review patch. If anyone has any objections, please let me know.

------------------

From: "Rafael J. Wysocki" <rjw@xxxxxxx>

commit 55d7ec4520e86d735d178c15d7df33d507bd43c6 upstream.

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 <rjw@xxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/base/power/runtime.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

--- a/drivers/base/power/runtime.c
+++ b/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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