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-rw-r--r--drivers/base/platform.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 30480f6f2af..869ff8c0014 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -160,6 +160,11 @@ static void platform_device_release(struct device *dev)
*
* Create a platform device object which can have other objects attached
* to it, and which will have attached objects freed when it is released.
+ *
+ * This device will be marked as not supporting hotpluggable drivers; no
+ * device add/remove uevents will be generated. In the unusual case that
+ * the device isn't being dynamically allocated as a legacy "probe the
+ * hardware" driver, infrastructure code should reverse this marking.
*/
struct platform_device *platform_device_alloc(const char *name, unsigned int id)
{
@@ -172,6 +177,12 @@ struct platform_device *platform_device_alloc(const char *name, unsigned int id)
pa->pdev.id = id;
device_initialize(&pa->pdev.dev);
pa->pdev.dev.release = platform_device_release;
+
+ /* prevent hotplug "modprobe $(MODALIAS)" from causing trouble in
+ * legacy probe-the-hardware drivers, which don't properly split
+ * out device enumeration logic from drivers.
+ */
+ pa->pdev.dev.uevent_suppress = 1;
}
return pa ? &pa->pdev : NULL;
@@ -292,20 +303,22 @@ EXPORT_SYMBOL_GPL(platform_device_add);
* @pdev: platform device we're removing
*
* Note that this function will also release all memory- and port-based
- * resources owned by the device (@dev->resource).
+ * resources owned by the device (@dev->resource). This function
+ * must _only_ be externally called in error cases. All other usage
+ * is a bug.
*/
void platform_device_del(struct platform_device *pdev)
{
int i;
if (pdev) {
+ device_del(&pdev->dev);
+
for (i = 0; i < pdev->num_resources; i++) {
struct resource *r = &pdev->resource[i];
if (r->flags & (IORESOURCE_MEM|IORESOURCE_IO))
release_resource(r);
}
-
- device_del(&pdev->dev);
}
}
EXPORT_SYMBOL_GPL(platform_device_del);
@@ -347,8 +360,15 @@ EXPORT_SYMBOL_GPL(platform_device_unregister);
* This function creates a simple platform device that requires minimal
* resource and memory management. Canned release function freeing
* memory allocated for the device allows drivers using such devices
- * to be unloaded iwithout waiting for the last reference to the device
+ * to be unloaded without waiting for the last reference to the device
* to be dropped.
+ *
+ * This interface is primarily intended for use with legacy drivers
+ * which probe hardware directly. Because such drivers create sysfs
+ * device nodes themselves, rather than letting system infrastructure
+ * handle such device enumeration tasks, they don't fully conform to
+ * the Linux driver model. In particular, when such drivers are built
+ * as modules, they can't be "hotplugged".
*/
struct platform_device *platform_device_register_simple(char *name, unsigned int id,
struct resource *res, unsigned int num)