Merge branch 'pm-domains'

* pm-domains:
  PM / domains: Improve wording of dev_pm_domain_attach() comment
  PM / Domains: Don't return -EEXIST at attach when PM domain exists
  spi: Respect all error codes from dev_pm_domain_attach()
  soundwire: Respect all error codes from dev_pm_domain_attach()
  mmc: sdio: Respect all error codes from dev_pm_domain_attach()
  i2c: Respect all error codes from dev_pm_domain_attach()
  driver core: Respect all error codes from dev_pm_domain_attach()
  amba: Respect all error codes from dev_pm_domain_attach()
  PM / Domains: Allow a better error handling of dev_pm_domain_attach()
  PM / Domains: Check for existing PM domain in dev_pm_domain_attach()
  PM / Domains: Drop redundant code in genpd while attaching devices
  PM / Domains: Drop comment in genpd about legacy Samsung DT binding
  PM / Domains: Fix error path during attach in genpd

Author: rafaeljw

drivers/acpi/device_pm.c

@@ -1257,18 +1257,15 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on)
 	struct acpi_device *adev = ACPI_COMPANION(dev);
 
 	if (!adev)
-		return -ENODEV;
-
-	if (dev->pm_domain)
-		return -EEXIST;
+		return 0;
 
 	/*
 	 * Only attach the power domain to the first device if the
 	 * companion is shared by multiple. This is to prevent doing power
 	 * management twice.
 	 */
 	if (!acpi_device_is_first_physical_node(adev, dev))
-		return -EBUSY;
+		return 0;
 
 	acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
 	dev_pm_domain_set(dev, &acpi_general_pm_domain);
@@ -1278,7 +1275,7 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on)
 	}
 
 	dev->pm_domain->detach = acpi_dev_pm_detach;
-	return 0;
+	return 1;
 }
 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
 #endif /* CONFIG_PM */

drivers/amba/bus.c

@@ -248,7 +248,7 @@ static int amba_probe(struct device *dev)
 			break;
 
 		ret = dev_pm_domain_attach(dev, true);
-		if (ret == -EPROBE_DEFER)
+		if (ret)
 			break;
 
 		ret = amba_get_enable_pclk(pcdev);
@@ -375,7 +375,7 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent)
 	}
 
 	ret = dev_pm_domain_attach(&dev->dev, true);
-	if (ret == -EPROBE_DEFER) {
+	if (ret) {
 		iounmap(tmp);
 		goto err_release;
 	}

drivers/base/platform.c

@@ -572,17 +572,16 @@ static int platform_drv_probe(struct device *_dev)
 		return ret;
 
 	ret = dev_pm_domain_attach(_dev, true);
-	if (ret != -EPROBE_DEFER) {
-		if (drv->probe) {
-			ret = drv->probe(dev);
-			if (ret)
-				dev_pm_domain_detach(_dev, true);
-		} else {
-			/* don't fail if just dev_pm_domain_attach failed */
-			ret = 0;
-		}
+	if (ret)
+		goto out;
+
+	if (drv->probe) {
+		ret = drv->probe(dev);
+		if (ret)
+			dev_pm_domain_detach(_dev, true);
 	}
 
+out:
 	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
 		dev_warn(_dev, "probe deferral not supported\n");
 		ret = -ENXIO;

drivers/base/power/common.c

@@ -98,17 +98,21 @@ EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
  * Callers must ensure proper synchronization of this function with power
  * management callbacks.
  *
- * Returns 0 on successfully attached PM domain or negative error code.
+ * Returns 0 on successfully attached PM domain, or when it is found that the
+ * device doesn't need a PM domain, else a negative error code.
  */
 int dev_pm_domain_attach(struct device *dev, bool power_on)
 {
 	int ret;
 
+	if (dev->pm_domain)
+		return 0;
+
 	ret = acpi_dev_pm_attach(dev, power_on);
-	if (ret)
+	if (!ret)
 		ret = genpd_dev_pm_attach(dev);
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
 

drivers/base/power/domain.c

@@ -1377,7 +1377,7 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 			    struct gpd_timing_data *td)
 {
 	struct generic_pm_domain_data *gpd_data;
-	int ret = 0;
+	int ret;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
@@ -1390,11 +1390,6 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 
 	genpd_lock(genpd);
 
-	if (genpd->prepared_count > 0) {
-		ret = -EAGAIN;
-		goto out;
-	}
-
 	ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
 	if (ret)
 		goto out;
@@ -2185,31 +2180,25 @@ static void genpd_dev_pm_sync(struct device *dev)
  * Parse device's OF node to find a PM domain specifier. If such is found,
  * attaches the device to retrieved pm_domain ops.
  *
- * Both generic and legacy Samsung-specific DT bindings are supported to keep
- * backwards compatibility with existing DTBs.
- *
- * Returns 0 on successfully attached PM domain or negative error code. Note
- * that if a power-domain exists for the device, but it cannot be found or
- * turned on, then return -EPROBE_DEFER to ensure that the device is not
- * probed and to re-try again later.
+ * Returns 1 on successfully attached PM domain, 0 when the device don't need a
+ * PM domain or a negative error code in case of failures. Note that if a
+ * power-domain exists for the device, but it cannot be found or turned on,
+ * then return -EPROBE_DEFER to ensure that the device is not probed and to
+ * re-try again later.
  */
 int genpd_dev_pm_attach(struct device *dev)
 {
 	struct of_phandle_args pd_args;
 	struct generic_pm_domain *pd;
-	unsigned int i;
 	int ret;
 
 	if (!dev->of_node)
-		return -ENODEV;
-
-	if (dev->pm_domain)
-		return -EEXIST;
+		return 0;
 
 	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
 					"#power-domain-cells", 0, &pd_args);
 	if (ret < 0)
-		return ret;
+		return 0;
 
 	mutex_lock(&gpd_list_lock);
 	pd = genpd_get_from_provider(&pd_args);
@@ -2223,21 +2212,14 @@ int genpd_dev_pm_attach(struct device *dev)
 
 	dev_dbg(dev, "adding to PM domain %s\n", pd->name);
 
-	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
-		ret = genpd_add_device(pd, dev, NULL);
-		if (ret != -EAGAIN)
-			break;
-
-		mdelay(i);
-		cond_resched();
-	}
+	ret = genpd_add_device(pd, dev, NULL);
 	mutex_unlock(&gpd_list_lock);
 
 	if (ret < 0) {
 		if (ret != -EPROBE_DEFER)
 			dev_err(dev, "failed to add to PM domain %s: %d",
 				pd->name, ret);
-		goto out;
+		return ret;
 	}
 
 	dev->pm_domain->detach = genpd_dev_pm_detach;
@@ -2246,8 +2228,11 @@ int genpd_dev_pm_attach(struct device *dev)
 	genpd_lock(pd);
 	ret = genpd_power_on(pd, 0);
 	genpd_unlock(pd);
-out:
-	return ret ? -EPROBE_DEFER : 0;
+
+	if (ret)
+		genpd_remove_device(pd, dev);
+
+	return ret ? -EPROBE_DEFER : 1;
 }
 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 

drivers/i2c/i2c-core-base.c

@@ -363,7 +363,7 @@ static int i2c_device_probe(struct device *dev)
 		goto err_clear_wakeup_irq;
 
 	status = dev_pm_domain_attach(&client->dev, true);
-	if (status == -EPROBE_DEFER)
+	if (status)
 		goto err_clear_wakeup_irq;
 
 	/*

drivers/mmc/core/sdio_bus.c

@@ -139,7 +139,7 @@ static int sdio_bus_probe(struct device *dev)
 		return -ENODEV;
 
 	ret = dev_pm_domain_attach(dev, false);
-	if (ret == -EPROBE_DEFER)
+	if (ret)
 		return ret;
 
 	/* Unbound SDIO functions are always suspended.

drivers/soundwire/bus_type.c

@@ -83,17 +83,16 @@ static int sdw_drv_probe(struct device *dev)
 	 * attach to power domain but don't turn on (last arg)
 	 */
 	ret = dev_pm_domain_attach(dev, false);
-	if (ret != -EPROBE_DEFER) {
-		ret = drv->probe(slave, id);
-		if (ret) {
-			dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret);
-			dev_pm_domain_detach(dev, false);
-		}
-	}
-
 	if (ret)
 		return ret;
 
+	ret = drv->probe(slave, id);
+	if (ret) {
+		dev_err(dev, "Probe of %s failed: %d\n", drv->name, ret);
+		dev_pm_domain_detach(dev, false);
+		return ret;
+	}
+
 	/* device is probed so let's read the properties now */
 	if (slave->ops && slave->ops->read_prop)
 		slave->ops->read_prop(slave);

drivers/spi/spi.c

@@ -356,11 +356,12 @@ static int spi_drv_probe(struct device *dev)
 	}
 
 	ret = dev_pm_domain_attach(dev, true);
-	if (ret != -EPROBE_DEFER) {
-		ret = sdrv->probe(spi);
-		if (ret)
-			dev_pm_domain_detach(dev, true);
-	}
+	if (ret)
+		return ret;
+
+	ret = sdrv->probe(spi);
+	if (ret)
+		dev_pm_domain_detach(dev, true);
 
 	return ret;
 }

include/linux/acpi.h

@@ -899,7 +899,7 @@ static inline int acpi_subsys_runtime_suspend(struct device *dev) { return 0; }
 static inline int acpi_subsys_runtime_resume(struct device *dev) { return 0; }
 static inline int acpi_dev_pm_attach(struct device *dev, bool power_on)
 {
-	return -ENODEV;
+	return 0;
 }
 #endif