Re: [PATCH 1/2, v2] PM / Runtime: Rework the "runtime idle" helper routine

[Aaron Lu <aaron.lwe@gmail.com>]

On 06/03/2013 05:52 AM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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.

For ATA and SCSI part:
Reviewed-by: Aaron Lu <aaron.lu@intel.com>

Thanks,
Aaron

> 
> 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>
> ---
>  Documentation/power/runtime_pm.txt |    5 -----
>  arch/arm/mach-omap2/omap_device.c  |    7 +------
>  drivers/acpi/device_pm.c           |    1 -
>  drivers/amba/bus.c                 |    2 +-
>  drivers/ata/libata-core.c          |    2 +-
>  drivers/base/platform.c            |    1 -
>  drivers/base/power/domain.c        |    1 -
>  drivers/base/power/generic_ops.c   |   23 -----------------------
>  drivers/base/power/runtime.c       |   12 +++++-------
>  drivers/dma/intel_mid_dma.c        |    2 +-
>  drivers/gpio/gpio-langwell.c       |    6 +-----
>  drivers/i2c/i2c-core.c             |    2 +-
>  drivers/mfd/ab8500-gpadc.c         |    8 +-------
>  drivers/mmc/core/bus.c             |    2 +-
>  drivers/mmc/core/sdio_bus.c        |    2 +-
>  drivers/pci/pci-driver.c           |   14 +++++---------
>  drivers/scsi/scsi_pm.c             |   11 +++--------
>  drivers/sh/pm_runtime.c            |    2 +-
>  drivers/spi/spi.c                  |    2 +-
>  drivers/tty/serial/mfd.c           |    9 ++-------
>  drivers/usb/core/driver.c          |    3 ++-
>  drivers/usb/core/port.c            |    1 -
>  include/linux/pm_runtime.h         |    2 --
>  23 files changed, 28 insertions(+), 92 deletions(-)
> 
> Index: linux-pm/drivers/base/power/runtime.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/runtime.c
> +++ linux-pm/drivers/base/power/runtime.c
> @@ -293,11 +293,8 @@ static int rpm_idle(struct device *dev,
>  	/* Pending requests need to be canceled. */
>  	dev->power.request = RPM_REQ_NONE;
>  
> -	if (dev->power.no_callbacks) {
> -		/* Assume ->runtime_idle() callback would have suspended. */
> -		retval = rpm_suspend(dev, rpmflags);
> +	if (dev->power.no_callbacks)
>  		goto out;
> -	}
>  
>  	/* Carry out an asynchronous or a synchronous idle notification. */
>  	if (rpmflags & RPM_ASYNC) {
> @@ -306,7 +303,8 @@ static int rpm_idle(struct device *dev,
>  			dev->power.request_pending = true;
>  			queue_work(pm_wq, &dev->power.work);
>  		}
> -		goto out;
> +		trace_rpm_return_int(dev, _THIS_IP_, 0);
> +		return 0;
>  	}
>  
>  	dev->power.idle_notification = true;
> @@ -326,14 +324,14 @@ static int rpm_idle(struct device *dev,
>  		callback = dev->driver->pm->runtime_idle;
>  
>  	if (callback)
> -		__rpm_callback(callback, dev);
> +		retval = __rpm_callback(callback, dev);
>  
>  	dev->power.idle_notification = false;
>  	wake_up_all(&dev->power.wait_queue);
>  
>   out:
>  	trace_rpm_return_int(dev, _THIS_IP_, retval);
> -	return retval;
> +	return retval ? retval : rpm_suspend(dev, rpmflags);
>  }
>  
>  /**
> Index: linux-pm/drivers/base/power/generic_ops.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/generic_ops.c
> +++ linux-pm/drivers/base/power/generic_ops.c
> @@ -12,29 +12,6 @@
>  
>  #ifdef CONFIG_PM_RUNTIME
>  /**
> - * pm_generic_runtime_idle - Generic runtime idle callback for subsystems.
> - * @dev: Device to handle.
> - *
> - * If PM operations are defined for the @dev's driver and they include
> - * ->runtime_idle(), execute it and return its error code, if nonzero.
> - * Otherwise, execute pm_runtime_suspend() for the device and return 0.
> - */
> -int pm_generic_runtime_idle(struct device *dev)
> -{
> -	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
> -
> -	if (pm && pm->runtime_idle) {
> -		int ret = pm->runtime_idle(dev);
> -		if (ret)
> -			return ret;
> -	}
> -
> -	pm_runtime_suspend(dev);
> -	return 0;
> -}
> -EXPORT_SYMBOL_GPL(pm_generic_runtime_idle);
> -
> -/**
>   * pm_generic_runtime_suspend - Generic runtime suspend callback for subsystems.
>   * @dev: Device to suspend.
>   *
> Index: linux-pm/include/linux/pm_runtime.h
> ===================================================================
> --- linux-pm.orig/include/linux/pm_runtime.h
> +++ linux-pm/include/linux/pm_runtime.h
> @@ -37,7 +37,6 @@ extern void pm_runtime_enable(struct dev
>  extern void __pm_runtime_disable(struct device *dev, bool check_resume);
>  extern void pm_runtime_allow(struct device *dev);
>  extern void pm_runtime_forbid(struct device *dev);
> -extern int pm_generic_runtime_idle(struct device *dev);
>  extern int pm_generic_runtime_suspend(struct device *dev);
>  extern int pm_generic_runtime_resume(struct device *dev);
>  extern void pm_runtime_no_callbacks(struct device *dev);
> @@ -143,7 +142,6 @@ static inline bool pm_runtime_active(str
>  static inline bool pm_runtime_status_suspended(struct device *dev) { return false; }
>  static inline bool pm_runtime_enabled(struct device *dev) { return false; }
>  
> -static inline int pm_generic_runtime_idle(struct device *dev) { return 0; }
>  static inline int pm_generic_runtime_suspend(struct device *dev) { return 0; }
>  static inline int pm_generic_runtime_resume(struct device *dev) { return 0; }
>  static inline void pm_runtime_no_callbacks(struct device *dev) {}
> Index: linux-pm/arch/arm/mach-omap2/omap_device.c
> ===================================================================
> --- linux-pm.orig/arch/arm/mach-omap2/omap_device.c
> +++ linux-pm/arch/arm/mach-omap2/omap_device.c
> @@ -591,11 +591,6 @@ static int _od_runtime_suspend(struct de
>  	return ret;
>  }
>  
> -static int _od_runtime_idle(struct device *dev)
> -{
> -	return pm_generic_runtime_idle(dev);
> -}
> -
>  static int _od_runtime_resume(struct device *dev)
>  {
>  	struct platform_device *pdev = to_platform_device(dev);
> @@ -653,7 +648,7 @@ static int _od_resume_noirq(struct devic
>  struct dev_pm_domain omap_device_pm_domain = {
>  	.ops = {
>  		SET_RUNTIME_PM_OPS(_od_runtime_suspend, _od_runtime_resume,
> -				   _od_runtime_idle)
> +				   NULL)
>  		USE_PLATFORM_PM_SLEEP_OPS
>  		.suspend_noirq = _od_suspend_noirq,
>  		.resume_noirq = _od_resume_noirq,
> Index: linux-pm/drivers/acpi/device_pm.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/device_pm.c
> +++ linux-pm/drivers/acpi/device_pm.c
> @@ -886,7 +886,6 @@ static struct dev_pm_domain acpi_general
>  #ifdef CONFIG_PM_RUNTIME
>  		.runtime_suspend = acpi_subsys_runtime_suspend,
>  		.runtime_resume = acpi_subsys_runtime_resume,
> -		.runtime_idle = pm_generic_runtime_idle,
>  #endif
>  #ifdef CONFIG_PM_SLEEP
>  		.prepare = acpi_subsys_prepare,
> Index: linux-pm/drivers/amba/bus.c
> ===================================================================
> --- linux-pm.orig/drivers/amba/bus.c
> +++ linux-pm/drivers/amba/bus.c
> @@ -284,7 +284,7 @@ static const struct dev_pm_ops amba_pm =
>  	SET_RUNTIME_PM_OPS(
>  		amba_pm_runtime_suspend,
>  		amba_pm_runtime_resume,
> -		pm_generic_runtime_idle
> +		NULL
>  	)
>  };
>  
> Index: linux-pm/drivers/base/power/domain.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/domain.c
> +++ linux-pm/drivers/base/power/domain.c
> @@ -2143,7 +2143,6 @@ void pm_genpd_init(struct generic_pm_dom
>  	genpd->max_off_time_changed = true;
>  	genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
>  	genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
> -	genpd->domain.ops.runtime_idle = pm_generic_runtime_idle;
>  	genpd->domain.ops.prepare = pm_genpd_prepare;
>  	genpd->domain.ops.suspend = pm_genpd_suspend;
>  	genpd->domain.ops.suspend_late = pm_genpd_suspend_late;
> Index: linux-pm/drivers/base/platform.c
> ===================================================================
> --- linux-pm.orig/drivers/base/platform.c
> +++ linux-pm/drivers/base/platform.c
> @@ -888,7 +888,6 @@ int platform_pm_restore(struct device *d
>  static const struct dev_pm_ops platform_dev_pm_ops = {
>  	.runtime_suspend = pm_generic_runtime_suspend,
>  	.runtime_resume = pm_generic_runtime_resume,
> -	.runtime_idle = pm_generic_runtime_idle,
>  	USE_PLATFORM_PM_SLEEP_OPS
>  };
>  
> Index: linux-pm/drivers/i2c/i2c-core.c
> ===================================================================
> --- linux-pm.orig/drivers/i2c/i2c-core.c
> +++ linux-pm/drivers/i2c/i2c-core.c
> @@ -435,7 +435,7 @@ static const struct dev_pm_ops i2c_devic
>  	SET_RUNTIME_PM_OPS(
>  		pm_generic_runtime_suspend,
>  		pm_generic_runtime_resume,
> -		pm_generic_runtime_idle
> +		NULL
>  	)
>  };
>  
> Index: linux-pm/drivers/mmc/core/sdio_bus.c
> ===================================================================
> --- linux-pm.orig/drivers/mmc/core/sdio_bus.c
> +++ linux-pm/drivers/mmc/core/sdio_bus.c
> @@ -211,7 +211,7 @@ static const struct dev_pm_ops sdio_bus_
>  	SET_RUNTIME_PM_OPS(
>  		pm_generic_runtime_suspend,
>  		pm_generic_runtime_resume,
> -		pm_generic_runtime_idle
> +		NULL
>  	)
>  };
>  
> Index: linux-pm/drivers/spi/spi.c
> ===================================================================
> --- linux-pm.orig/drivers/spi/spi.c
> +++ linux-pm/drivers/spi/spi.c
> @@ -223,7 +223,7 @@ static const struct dev_pm_ops spi_pm =
>  	SET_RUNTIME_PM_OPS(
>  		pm_generic_runtime_suspend,
>  		pm_generic_runtime_resume,
> -		pm_generic_runtime_idle
> +		NULL
>  	)
>  };
>  
> Index: linux-pm/drivers/usb/core/port.c
> ===================================================================
> --- linux-pm.orig/drivers/usb/core/port.c
> +++ linux-pm/drivers/usb/core/port.c
> @@ -141,7 +141,6 @@ static const struct dev_pm_ops usb_port_
>  #ifdef CONFIG_PM_RUNTIME
>  	.runtime_suspend =	usb_port_runtime_suspend,
>  	.runtime_resume =	usb_port_runtime_resume,
> -	.runtime_idle =		pm_generic_runtime_idle,
>  #endif
>  };
>  
> Index: linux-pm/Documentation/power/runtime_pm.txt
> ===================================================================
> --- linux-pm.orig/Documentation/power/runtime_pm.txt
> +++ linux-pm/Documentation/power/runtime_pm.txt
> @@ -660,11 +660,6 @@ Subsystems may wish to conserve code spa
>  management callbacks provided by the PM core, defined in
>  driver/base/power/generic_ops.c:
>  
> -  int pm_generic_runtime_idle(struct device *dev);
> -    - invoke the ->runtime_idle() callback provided by the driver of this
> -      device, if defined, and call pm_runtime_suspend() for this device if the
> -      return value is 0 or the callback is not defined
> -
>    int pm_generic_runtime_suspend(struct device *dev);
>      - invoke the ->runtime_suspend() callback provided by the driver of this
>        device and return its result, or return -EINVAL if not defined
> Index: linux-pm/drivers/usb/core/driver.c
> ===================================================================
> --- linux-pm.orig/drivers/usb/core/driver.c
> +++ linux-pm/drivers/usb/core/driver.c
> @@ -1765,7 +1765,8 @@ int usb_runtime_idle(struct device *dev)
>  	 */
>  	if (autosuspend_check(udev) == 0)
>  		pm_runtime_autosuspend(dev);
> -	return 0;
> +	/* Tell the core not to suspend it, though. */
> +	return -EBUSY;
>  }
>  
>  int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
> Index: linux-pm/drivers/pci/pci-driver.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci-driver.c
> +++ linux-pm/drivers/pci/pci-driver.c
> @@ -1050,26 +1050,22 @@ static int pci_pm_runtime_idle(struct de
>  {
>  	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 */
> Index: linux-pm/drivers/ata/libata-core.c
> ===================================================================
> --- linux-pm.orig/drivers/ata/libata-core.c
> +++ linux-pm/drivers/ata/libata-core.c
> @@ -5430,7 +5430,7 @@ static int ata_port_runtime_idle(struct
>  				return -EBUSY;
>  	}
>  
> -	return pm_runtime_suspend(dev);
> +	return 0;
>  }
>  
>  static int ata_port_runtime_suspend(struct device *dev)
> Index: linux-pm/drivers/dma/intel_mid_dma.c
> ===================================================================
> --- linux-pm.orig/drivers/dma/intel_mid_dma.c
> +++ linux-pm/drivers/dma/intel_mid_dma.c
> @@ -1405,7 +1405,7 @@ static int dma_runtime_idle(struct devic
>  			return -EAGAIN;
>  	}
>  
> -	return pm_schedule_suspend(dev, 0);
> +	return 0;
>  }
>  
>  /******************************************************************************
> Index: linux-pm/drivers/gpio/gpio-langwell.c
> ===================================================================
> --- linux-pm.orig/drivers/gpio/gpio-langwell.c
> +++ linux-pm/drivers/gpio/gpio-langwell.c
> @@ -305,11 +305,7 @@ static const struct irq_domain_ops lnw_g
>  
>  static int lnw_gpio_runtime_idle(struct device *dev)
>  {
> -	int err = pm_schedule_suspend(dev, 500);
> -
> -	if (!err)
> -		return 0;
> -
> +	pm_schedule_suspend(dev, 500);
>  	return -EBUSY;
>  }
>  
> Index: linux-pm/drivers/mfd/ab8500-gpadc.c
> ===================================================================
> --- linux-pm.orig/drivers/mfd/ab8500-gpadc.c
> +++ linux-pm/drivers/mfd/ab8500-gpadc.c
> @@ -886,12 +886,6 @@ static int ab8500_gpadc_runtime_resume(s
>  	return ret;
>  }
>  
> -static int ab8500_gpadc_runtime_idle(struct device *dev)
> -{
> -	pm_runtime_suspend(dev);
> -	return 0;
> -}
> -
>  static int ab8500_gpadc_suspend(struct device *dev)
>  {
>  	struct ab8500_gpadc *gpadc = dev_get_drvdata(dev);
> @@ -1039,7 +1033,7 @@ static int ab8500_gpadc_remove(struct pl
>  static const struct dev_pm_ops ab8500_gpadc_pm_ops = {
>  	SET_RUNTIME_PM_OPS(ab8500_gpadc_runtime_suspend,
>  			   ab8500_gpadc_runtime_resume,
> -			   ab8500_gpadc_runtime_idle)
> +			   NULL)
>  	SET_SYSTEM_SLEEP_PM_OPS(ab8500_gpadc_suspend,
>  				ab8500_gpadc_resume)
>  
> Index: linux-pm/drivers/mmc/core/bus.c
> ===================================================================
> --- linux-pm.orig/drivers/mmc/core/bus.c
> +++ linux-pm/drivers/mmc/core/bus.c
> @@ -164,7 +164,7 @@ static int mmc_runtime_resume(struct dev
>  
>  static int mmc_runtime_idle(struct device *dev)
>  {
> -	return pm_runtime_suspend(dev);
> +	return 0;
>  }
>  
>  #endif /* !CONFIG_PM_RUNTIME */
> Index: linux-pm/drivers/scsi/scsi_pm.c
> ===================================================================
> --- linux-pm.orig/drivers/scsi/scsi_pm.c
> +++ linux-pm/drivers/scsi/scsi_pm.c
> @@ -229,8 +229,6 @@ static int scsi_runtime_resume(struct de
>  
>  static int scsi_runtime_idle(struct device *dev)
>  {
> -	int err;
> -
>  	dev_dbg(dev, "scsi_runtime_idle\n");
>  
>  	/* Insert hooks here for targets, hosts, and transport classes */
> @@ -240,14 +238,11 @@ static int scsi_runtime_idle(struct devi
>  
>  		if (sdev->request_queue->dev) {
>  			pm_runtime_mark_last_busy(dev);
> -			err = pm_runtime_autosuspend(dev);
> -		} else {
> -			err = pm_runtime_suspend(dev);
> +			pm_runtime_autosuspend(dev);
> +			return -EBUSY;
>  		}
> -	} else {
> -		err = pm_runtime_suspend(dev);
>  	}
> -	return err;
> +	return 0;
>  }
>  
>  int scsi_autopm_get_device(struct scsi_device *sdev)
> Index: linux-pm/drivers/sh/pm_runtime.c
> ===================================================================
> --- linux-pm.orig/drivers/sh/pm_runtime.c
> +++ linux-pm/drivers/sh/pm_runtime.c
> @@ -25,7 +25,7 @@
>  static int default_platform_runtime_idle(struct device *dev)
>  {
>  	/* suspend synchronously to disable clocks immediately */
> -	return pm_runtime_suspend(dev);
> +	return 0;
>  }
>  
>  static struct dev_pm_domain default_pm_domain = {
> Index: linux-pm/drivers/tty/serial/mfd.c
> ===================================================================
> --- linux-pm.orig/drivers/tty/serial/mfd.c
> +++ linux-pm/drivers/tty/serial/mfd.c
> @@ -1248,13 +1248,8 @@ static int serial_hsu_resume(struct pci_
>  #ifdef CONFIG_PM_RUNTIME
>  static int serial_hsu_runtime_idle(struct device *dev)
>  {
> -	int err;
> -
> -	err = pm_schedule_suspend(dev, 500);
> -	if (err)
> -		return -EBUSY;
> -
> -	return 0;
> +	pm_schedule_suspend(dev, 500);
> +	return -EBUSY;
>  }
>  
>  static int serial_hsu_runtime_suspend(struct device *dev)
> 
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