On Tuesday, June 08, 2010, Alan Stern wrote:
> 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@xxxxxxxxxxxxxxxxxxx>
> CC: Rafael J. Wysocki <rjw@xxxxxxx>
Acked-by: Rafael J. Wysocki <rjw@xxxxxxx>
Jesse, please queue up for 2.6.36.
Rafael
> ---
>
> Index: usb-2.6/drivers/pci/pci-driver.c
> ===================================================================
> --- usb-2.6.orig/drivers/pci/pci-driver.c
> +++ usb-2.6/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;
> + struct device *dev = &ddi->dev->dev;
> + int rc;
>
> - return ddi->drv->probe(ddi->dev, ddi->id);
> + /* 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 devi
> 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.
> Index: usb-2.6/drivers/net/e1000e/netdev.c
> ===================================================================
> --- usb-2.6.orig/drivers/net/e1000e/netdev.c
> +++ usb-2.6/drivers/net/e1000e/netdev.c
> @@ -5721,11 +5721,8 @@ static int __devinit e1000_probe(struct
>
> e1000_print_device_info(adapter);
>
> - if (pci_dev_run_wake(pdev)) {
> - pm_runtime_set_active(&pdev->dev);
> - pm_runtime_enable(&pdev->dev);
> - }
> - pm_schedule_suspend(&pdev->dev, MSEC_PER_SEC);
> + if (pci_dev_run_wake(pdev))
> + pm_runtime_put_noidle(&pdev->dev);
>
> return 0;
>
> @@ -5771,8 +5768,6 @@ static void __devexit e1000_remove(struc
> struct e1000_adapter *adapter = netdev_priv(netdev);
> bool down = test_bit(__E1000_DOWN, &adapter->state);
>
> - pm_runtime_get_sync(&pdev->dev);
> -
> /*
> * flush_scheduled work may reschedule our watchdog task, so
> * explicitly disable watchdog tasks from being rescheduled
> @@ -5797,11 +5792,8 @@ static void __devexit e1000_remove(struc
> clear_bit(__E1000_DOWN, &adapter->state);
> unregister_netdev(netdev);
>
> - if (pci_dev_run_wake(pdev)) {
> - pm_runtime_disable(&pdev->dev);
> - pm_runtime_set_suspended(&pdev->dev);
> - }
> - pm_runtime_put_noidle(&pdev->dev);
> + if (pci_dev_run_wake(pdev))
> + pm_runtime_get_noresume(&pdev->dev);
>
> /*
> * Release control of h/w to f/w. If f/w is AMT enabled, this
> Index: usb-2.6/drivers/net/r8169.c
> ===================================================================
> --- usb-2.6.orig/drivers/net/r8169.c
> +++ usb-2.6/drivers/net/r8169.c
> @@ -3208,11 +3208,8 @@ rtl8169_init_one(struct pci_dev *pdev, c
>
> device_set_wakeup_enable(&pdev->dev, tp->features & RTL_FEATURE_WOL);
>
> - if (pci_dev_run_wake(pdev)) {
> - pm_runtime_set_active(&pdev->dev);
> - pm_runtime_enable(&pdev->dev);
> - }
> - pm_runtime_idle(&pdev->dev);
> + if (pci_dev_run_wake(pdev))
> + pm_runtime_put_noidle(&pdev->dev);
>
> out:
> return rc;
> @@ -3235,17 +3232,12 @@ static void __devexit rtl8169_remove_one
> struct net_device *dev = pci_get_drvdata(pdev);
> struct rtl8169_private *tp = netdev_priv(dev);
>
> - pm_runtime_get_sync(&pdev->dev);
> -
> flush_scheduled_work();
>
> unregister_netdev(dev);
>
> - if (pci_dev_run_wake(pdev)) {
> - pm_runtime_disable(&pdev->dev);
> - pm_runtime_set_suspended(&pdev->dev);
> - }
> - pm_runtime_put_noidle(&pdev->dev);
> + if (pci_dev_run_wake(pdev))
> + pm_runtime_get_noresume(&pdev->dev);
>
> /* restore original MAC address */
> rtl_rar_set(tp, dev->perm_addr);
--
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