1 files changed, 90 insertions, 12 deletions

diff --git a/kernel/drivers/base/platform.c b/kernel/drivers/base/platform.c
index 7403de948..176b59f5b 100644
--- a/kernel/drivers/base/platform.c
+++ b/kernel/drivers/base/platform.c
@@ -514,9 +514,14 @@ static int platform_drv_probe(struct device *_dev)
 
 	ret = dev_pm_domain_attach(_dev, true);
 	if (ret != -EPROBE_DEFER) {
-		ret = drv->probe(dev);
-		if (ret)
-			dev_pm_domain_detach(_dev, true);
+		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 (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
@@ -536,9 +541,10 @@ static int platform_drv_remove(struct device *_dev)
 {
 	struct platform_driver *drv = to_platform_driver(_dev->driver);
 	struct platform_device *dev = to_platform_device(_dev);
-	int ret;
+	int ret = 0;
 
-	ret = drv->remove(dev);
+	if (drv->remove)
+		ret = drv->remove(dev);
 	dev_pm_domain_detach(_dev, true);
 
 	return ret;
@@ -549,7 +555,8 @@ static void platform_drv_shutdown(struct device *_dev)
 	struct platform_driver *drv = to_platform_driver(_dev->driver);
 	struct platform_device *dev = to_platform_device(_dev);
 
-	drv->shutdown(dev);
+	if (drv->shutdown)
+		drv->shutdown(dev);
 	dev_pm_domain_detach(_dev, true);
 }
 
@@ -563,12 +570,9 @@ int __platform_driver_register(struct platform_driver *drv,
 {
 	drv->driver.owner = owner;
 	drv->driver.bus = &platform_bus_type;
-	if (drv->probe)
-		drv->driver.probe = platform_drv_probe;
-	if (drv->remove)
-		drv->driver.remove = platform_drv_remove;
-	if (drv->shutdown)
-		drv->driver.shutdown = platform_drv_shutdown;
+	drv->driver.probe = platform_drv_probe;
+	drv->driver.remove = platform_drv_remove;
+	drv->driver.shutdown = platform_drv_shutdown;
 
 	return driver_register(&drv->driver);
 }
@@ -609,6 +613,19 @@ int __init_or_module __platform_driver_probe(struct platform_driver *drv,
 {
 	int retval, code;
 
+	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
+		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
+			 drv->driver.name, __func__);
+		return -EINVAL;
+	}
+
+	/*
+	 * We have to run our probes synchronously because we check if
+	 * we find any devices to bind to and exit with error if there
+	 * are any.
+	 */
+	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
+
 	/*
 	 * Prevent driver from requesting probe deferral to avoid further
 	 * futile probe attempts.
@@ -698,6 +715,67 @@ err_out:
 }
 EXPORT_SYMBOL_GPL(__platform_create_bundle);
 
+/**
+ * __platform_register_drivers - register an array of platform drivers
+ * @drivers: an array of drivers to register
+ * @count: the number of drivers to register
+ * @owner: module owning the drivers
+ *
+ * Registers platform drivers specified by an array. On failure to register a
+ * driver, all previously registered drivers will be unregistered. Callers of
+ * this API should use platform_unregister_drivers() to unregister drivers in
+ * the reverse order.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int __platform_register_drivers(struct platform_driver * const *drivers,
+				unsigned int count, struct module *owner)
+{
+	unsigned int i;
+	int err;
+
+	for (i = 0; i < count; i++) {
+		pr_debug("registering platform driver %ps\n", drivers[i]);
+
+		err = __platform_driver_register(drivers[i], owner);
+		if (err < 0) {
+			pr_err("failed to register platform driver %ps: %d\n",
+			       drivers[i], err);
+			goto error;
+		}
+	}
+
+	return 0;
+
+error:
+	while (i--) {
+		pr_debug("unregistering platform driver %ps\n", drivers[i]);
+		platform_driver_unregister(drivers[i]);
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(__platform_register_drivers);
+
+/**
+ * platform_unregister_drivers - unregister an array of platform drivers
+ * @drivers: an array of drivers to unregister
+ * @count: the number of drivers to unregister
+ *
+ * Unegisters platform drivers specified by an array. This is typically used
+ * to complement an earlier call to platform_register_drivers(). Drivers are
+ * unregistered in the reverse order in which they were registered.
+ */
+void platform_unregister_drivers(struct platform_driver * const *drivers,
+				 unsigned int count)
+{
+	while (count--) {
+		pr_debug("unregistering platform driver %ps\n", drivers[count]);
+		platform_driver_unregister(drivers[count]);
+	}
+}
+EXPORT_SYMBOL_GPL(platform_unregister_drivers);
+
 /* modalias support enables more hands-off userspace setup:
  * (a) environment variable lets new-style hotplug events work once system is
  *     fully running:  "modprobe $MODALIAS"