PM / Runtime: Check device PM QoS setting before "no callbacks" check
Rafael J. Wysocki [Wed, 15 Aug 2012 19:32:04 +0000 (21:32 +0200)]
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@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org
(cherry picked from commit 55d7ec4520e86d735d178c15d7df33d507bd43c6)
Change-Id: I02bbf2b76fc2881fdc13b0d885143a88addfc619
Reviewed-on: http://git-master/r/145854
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Tested-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

drivers/base/power/runtime.c

index db43d82..44bce74 100644 (file)
@@ -147,6 +147,8 @@ static int rpm_check_suspend_allowed(struct device *dev)
            || (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 *dev, int rpmflags)
                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)