PM / Runtime: Rework the "runtime idle" helper routine

The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0.  If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>

1 files changed, 5 insertions, 9 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 79277fb36c6b..e6515e21afa3 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1050,26 +1050,22 @@ static int pci_pm_runtime_idle(struct device *dev)
 {
         struct pci_dev *pci_dev = to_pci_dev(dev);
         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+        int ret = 0;
 
         /*
          * If pci_dev->driver is not set (unbound), the device should
          * always remain in D0 regardless of the runtime PM status
          */
         if (!pci_dev->driver)
-                goto out;
+                return 0;
 
         if (!pm)
                 return -ENOSYS;
 
-        if (pm->runtime_idle) {
-                int ret = pm->runtime_idle(dev);
-                if (ret)
-                        return ret;
-        }
+        if (pm->runtime_idle)
+                ret = pm->runtime_idle(dev);
 
-out:
-        pm_runtime_suspend(dev);
-        return 0;
+        return ret;
 }
 
 #else /* !CONFIG_PM_RUNTIME */