Driver core: Make platform_device.id an int

While platform_device.id is a u32, platform_device_add() handles "-1"
as a special id value. This has potential for confusion and bugs.
Making it an int instead should prevent problems from happening in
the future.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 8 insertions, 6 deletions

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index a2e3910196e0..fb5609241482 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -161,7 +161,7 @@ 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.
  */
-struct platform_device *platform_device_alloc(const char *name, unsigned int id)
+struct platform_device *platform_device_alloc(const char *name, int id)
 {
         struct platform_object *pa;
 
@@ -245,7 +245,8 @@ int platform_device_add(struct platform_device *pdev)
         pdev->dev.bus = &platform_bus_type;
 
         if (pdev->id != -1)
-                snprintf(pdev->dev.bus_id, BUS_ID_SIZE, "%s.%u", pdev->name, pdev->id);
+                snprintf(pdev->dev.bus_id, BUS_ID_SIZE, "%s.%d", pdev->name,
+                         pdev->id);
         else
                 strlcpy(pdev->dev.bus_id, pdev->name, BUS_ID_SIZE);
 
@@ -359,7 +360,7 @@ EXPORT_SYMBOL_GPL(platform_device_unregister);
  *      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 platform_device *platform_device_register_simple(char *name, int id,
                                                         struct resource *res, unsigned int num)
 {
         struct platform_device *pdev;
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 8bbd459eafdc..e80804316cdb 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -15,7 +15,7 @@
 
 struct platform_device {
         const char      * name;
-        u32             id;
+        int             id;
         struct device   dev;
         u32             num_resources;
         struct resource * resource;
@@ -35,9 +35,10 @@ extern struct resource *platform_get_resource_byname(struct platform_device *, u
 extern int platform_get_irq_byname(struct platform_device *, char *);
 extern int platform_add_devices(struct platform_device **, int);
 
-extern struct platform_device *platform_device_register_simple(char *, unsigned int, struct resource *, unsigned int);
+extern struct platform_device *platform_device_register_simple(char *, int id,
+                                        struct resource *, unsigned int);
 
-extern struct platform_device *platform_device_alloc(const char *name, unsigned int id);
+extern struct platform_device *platform_device_alloc(const char *name, int id);
 extern int platform_device_add_resources(struct platform_device *pdev, struct resource *res, unsigned int num);
 extern int platform_device_add_data(struct platform_device *pdev, const void *data, size_t size);
 extern int platform_device_add(struct platform_device *pdev);