of/platform: Fix of_platform_device_destroy iteration of devices

of_platform_destroy does not work properly, since the tree
population test was iterating on all devices having as its parent
the given platform device.

The check was intended to check whether any other platform or amba
devices created by of_platform_populate were still populated, but
instead checked for every kind of device. This is wrong, since platform
devices typically create a subsystem regular device and set themselves
as parents.

Instead, go ahead and call the unregister functions for any devices
created with of_platform_populate. The driver core will take care of
unbinding drivers, and drivers are responsible for getting rid of any
child devices that weren't created by of_platform_populate.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
(cherry picked from commit 75f353b61342b5847c7f6d8499fd6301dce09845)
Signed-off-by: Mark Brown <broonie@kernel.org>
Conflicts:
	include/linux/of_platform.h

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index e6790184a5d2452b845f2b3128b007da13d6c120..eb6e20597e82a6cc5ada5b70f78c14cd14d3377b 100644 (file)
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -401,6 +401,7 @@ static int of_platform_bus_create(struct device_node *bus,
                        break;
                }
        }
+       of_node_set_flag(bus, OF_POPULATED_BUS);
        return rc;
 }
 
@@ -487,19 +488,13 @@ EXPORT_SYMBOL_GPL(of_platform_populate);
 
 static int of_platform_device_destroy(struct device *dev, void *data)
 {
-       bool *children_left = data;
-
        /* Do not touch devices not populated from the device tree */
-       if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) {
-               *children_left = true;
+       if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
                return 0;
-       }
 
-       /* Recurse, but don't touch this device if it has any children left */
-       if (of_platform_depopulate(dev) != 0) {
-               *children_left = true;
-               return 0;
-       }
+       /* Recurse for any nodes that were treated as busses */
+       if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
+               device_for_each_child(dev, NULL, of_platform_device_destroy);
 
        if (dev->bus == &platform_bus_type)
                platform_device_unregister(to_platform_device(dev));
@@ -507,19 +502,15 @@ static int of_platform_device_destroy(struct device *dev, void *data)
        else if (dev->bus == &amba_bustype)
                amba_device_unregister(to_amba_device(dev));
 #endif
-       else {
-               *children_left = true;
-               return 0;
-       }
 
        of_node_clear_flag(dev->of_node, OF_POPULATED);
-
+       of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
        return 0;
 }
 
 /**
  * of_platform_depopulate() - Remove devices populated from device tree
- * @parent: device which childred will be removed
+ * @parent: device which children will be removed
  *
  * Complementary to of_platform_populate(), this function removes children
  * of the given device (and, recurrently, their children) that have been
@@ -529,14 +520,9 @@ static int of_platform_device_destroy(struct device *dev, void *data)
  * Returns 0 when all children devices have been removed or
  * -EBUSY when some children remained.
  */
-int of_platform_depopulate(struct device *parent)
+void of_platform_depopulate(struct device *parent)
 {
-       bool children_left = false;
-
-       device_for_each_child(parent, &children_left,
-                             of_platform_device_destroy);
-
-       return children_left ? -EBUSY : 0;
+       device_for_each_child(parent, NULL, of_platform_device_destroy);
 }
 EXPORT_SYMBOL_GPL(of_platform_depopulate);
 

diff --git a/include/linux/of.h b/include/linux/of.h
index 9755b7a470aab109986cd0cf3ca82b3a048a4bdc..f270a2041f2988dc4cbf85259592534101f53479 100644 (file)
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -206,6 +206,7 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size)
 #define OF_DYNAMIC     1 /* node and properties were allocated via kmalloc */
 #define OF_DETACHED    2 /* node has been detached from the device tree */
 #define OF_POPULATED   3 /* device already created for the node */
+#define OF_POPULATED_BUS       4 /* of_platform_populate recursed to children of this node */
 
 #define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags)
 #define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)

diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index d7ecf53462782f08bb1f6d8337858e3814276142..3e989ed04e3fc12cdea36298eaca5da371920ebb 100644 (file)
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -95,7 +95,7 @@ extern int of_platform_populate(struct device_node *root,
                                const struct of_device_id *matches,
                                const struct of_dev_auxdata *lookup,
                                struct device *parent);
-extern int of_platform_depopulate(struct device *parent);
+extern void of_platform_depopulate(struct device *parent);
 #endif /* CONFIG_OF_ADDRESS */
 
 #endif /* CONFIG_OF_DEVICE */
@@ -110,10 +110,7 @@ static inline int of_platform_populate(struct device_node *root,
 {
        return -ENODEV;
 }
-static inline int of_platform_depopulate(struct device *parent)
-{
-       return -ENODEV;
-}
+static inline void of_platform_depopulate(struct device *parent) { }
 #endif
 
 #endif /* _LINUX_OF_PLATFORM_H */