USB: add runtime PM for PCI-based host controllers

This patch (as1386) adds runtime-PM support for PCI-based USB host
controllers.  By default autosuspend is disallowed; the user must
enable it by writing "auto" to the controller's power/control sysfs
attribute.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 62 insertions, 14 deletions

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 352577baa53d..fe6b8d40a506 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -250,6 +250,9 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
         if (retval != 0)
                 goto err4;
         set_hs_companion(dev, hcd);
+
+        if (pci_dev_run_wake(dev))
+                pm_runtime_put_noidle(&dev->dev);
         return retval;
 
  err4:
@@ -292,6 +295,9 @@ void usb_hcd_pci_remove(struct pci_dev *dev)
         if (!hcd)
                 return;
 
+        if (pci_dev_run_wake(dev))
+                pm_runtime_get_noresume(&dev->dev);
+
         /* Fake an interrupt request in order to give the driver a chance
          * to test whether the controller hardware has been removed (e.g.,
          * cardbus physical eject).
@@ -325,12 +331,13 @@ void usb_hcd_pci_shutdown(struct pci_dev *dev)
         if (!hcd)
                 return;
 
-        if (hcd->driver->shutdown)
+        if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) &&
+                        hcd->driver->shutdown)
                 hcd->driver->shutdown(hcd);
 }
 EXPORT_SYMBOL_GPL(usb_hcd_pci_shutdown);
 
-#ifdef  CONFIG_PM_SLEEP
+#ifdef  CONFIG_PM_OPS
 
 #ifdef  CONFIG_PPC_PMAC
 static void powermac_set_asic(struct pci_dev *pci_dev, int enable)
@@ -366,7 +373,7 @@ static int check_root_hub_suspended(struct device *dev)
         return 0;
 }
 
-static int hcd_pci_suspend(struct device *dev)
+static int suspend_common(struct device *dev, bool do_wakeup)
 {
         struct pci_dev          *pci_dev = to_pci_dev(dev);
         struct usb_hcd          *hcd = pci_get_drvdata(pci_dev);
@@ -381,13 +388,7 @@ static int hcd_pci_suspend(struct device *dev)
         if (retval)
                 return retval;
 
-        /* We might already be suspended (runtime PM -- not yet written) */
-        if (pci_dev->current_state != PCI_D0)
-                return retval;
-
         if (hcd->driver->pci_suspend) {
-                bool    do_wakeup = device_may_wakeup(dev);
-
                 /* Optimization: Don't suspend if a root-hub wakeup is
                  * pending and it would cause the HCD to wake up anyway.
                  */
@@ -439,10 +440,8 @@ static int resume_common(struct device *dev, int event)
         clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
 
         if (hcd->driver->pci_resume) {
-                /* This call should be made only during system resume,
-                 * not during runtime resume.
-                 */
-                wait_for_companions(pci_dev, hcd);
+                if (event != PM_EVENT_AUTO_RESUME)
+                        wait_for_companions(pci_dev, hcd);
 
                 retval = hcd->driver->pci_resume(hcd,
                                 event == PM_EVENT_RESTORE);
@@ -454,6 +453,13 @@ static int resume_common(struct device *dev, int event)
         return retval;
 }
 
+#ifdef  CONFIG_PM_SLEEP
+
+static int hcd_pci_suspend(struct device *dev)
+{
+        return suspend_common(dev, device_may_wakeup(dev));
+}
+
 static int hcd_pci_suspend_noirq(struct device *dev)
 {
         struct pci_dev          *pci_dev = to_pci_dev(dev);
@@ -513,6 +519,46 @@ static int hcd_pci_restore(struct device *dev)
         return resume_common(dev, PM_EVENT_RESTORE);
 }
 
+#else
+
+#define hcd_pci_suspend         NULL
+#define hcd_pci_suspend_noirq   NULL
+#define hcd_pci_resume_noirq    NULL
+#define hcd_pci_resume          NULL
+#define hcd_pci_restore         NULL
+
+#endif  /* CONFIG_PM_SLEEP */
+
+#ifdef  CONFIG_PM_RUNTIME
+
+static int hcd_pci_runtime_suspend(struct device *dev)
+{
+        int     retval;
+
+        retval = suspend_common(dev, true);
+        if (retval == 0)
+                powermac_set_asic(to_pci_dev(dev), 0);
+        dev_dbg(dev, "hcd_pci_runtime_suspend: %d\n", retval);
+        return retval;
+}
+
+static int hcd_pci_runtime_resume(struct device *dev)
+{
+        int     retval;
+
+        powermac_set_asic(to_pci_dev(dev), 1);
+        retval = resume_common(dev, PM_EVENT_AUTO_RESUME);
+        dev_dbg(dev, "hcd_pci_runtime_resume: %d\n", retval);
+        return retval;
+}
+
+#else
+
+#define hcd_pci_runtime_suspend NULL
+#define hcd_pci_runtime_resume  NULL
+
+#endif  /* CONFIG_PM_RUNTIME */
+
 const struct dev_pm_ops usb_hcd_pci_pm_ops = {
         .suspend        = hcd_pci_suspend,
         .suspend_noirq  = hcd_pci_suspend_noirq,
@@ -526,7 +572,9 @@ const struct dev_pm_ops usb_hcd_pci_pm_ops = {
         .poweroff_noirq = hcd_pci_suspend_noirq,
         .restore_noirq  = hcd_pci_resume_noirq,
         .restore        = hcd_pci_restore,
+        .runtime_suspend = hcd_pci_runtime_suspend,
+        .runtime_resume = hcd_pci_runtime_resume,
 };
 EXPORT_SYMBOL_GPL(usb_hcd_pci_pm_ops);
 
-#endif  /* CONFIG_PM_SLEEP */
+#endif  /* CONFIG_PM_OPS */