PCI: change device runtime PM settings for probe and remove

This patch (as1388) changes the way the PCI core handles runtime PM
settings when probing or unbinding drivers.  Now the core will make
sure the device is enabled for runtime PM, with a usage count >= 1,
when a driver is probed.  It does the same when calling a driver's
remove method.

If the driver wants to use runtime PM, all it has to do is call
pm_runtime_pu_noidle() near the end of its probe routine (to cancel
the core's usage increment) and pm_runtime_get_noresume() near the
start of its remove routine (to restore the usage count).  It does not
need to mess around with setting the runtime state to enabled,
disabled, active, or suspended.

The patch updates e1000e and r8169, the only PCI drivers that already
use the existing runtime PM interface.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 29 insertions, 3 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index f9a0aec3abcf..8a6f797de8e5 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -289,8 +289,26 @@ struct drv_dev_and_id {
 static long local_pci_probe(void *_ddi)
 {
         struct drv_dev_and_id *ddi = _ddi;
-
-        return ddi->drv->probe(ddi->dev, ddi->id);
+        struct device *dev = &ddi->dev->dev;
+        int rc;
+
+        /* Unbound PCI devices are always set to disabled and suspended.
+         * During probe, the device is set to enabled and active and the
+         * usage count is incremented.  If the driver supports runtime PM,
+         * it should call pm_runtime_put_noidle() in its probe routine and
+         * pm_runtime_get_noresume() in its remove routine.
+         */
+        pm_runtime_get_noresume(dev);
+        pm_runtime_set_active(dev);
+        pm_runtime_enable(dev);
+
+        rc = ddi->drv->probe(ddi->dev, ddi->id);
+        if (rc) {
+                pm_runtime_disable(dev);
+                pm_runtime_set_suspended(dev);
+                pm_runtime_put_noidle(dev);
+        }
+        return rc;
 }
 
 static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
@@ -369,11 +387,19 @@ static int pci_device_remove(struct device * dev)
         struct pci_driver * drv = pci_dev->driver;
 
         if (drv) {
-                if (drv->remove)
+                if (drv->remove) {
+                        pm_runtime_get_sync(dev);
                         drv->remove(pci_dev);
+                        pm_runtime_put_noidle(dev);
+                }
                 pci_dev->driver = NULL;
         }
 
+        /* Undo the runtime PM settings in local_pci_probe() */
+        pm_runtime_disable(dev);
+        pm_runtime_set_suspended(dev);
+        pm_runtime_put_noidle(dev);
+
         /*
          * If the device is still on, set the power state as "unknown",
          * since it might change by the next time we load the driver.