[RFC PATCH 1/3] of/device: manage resources similar to platform_device_add

From: Suman Anna
Date: Wed Jan 07 2015 - 12:32:29 EST


Drivers can use of_platform_populate() to create platform devices
for children of the device main node, and a complementary API
of_platform_depopulate() is provided to delete these child platform
devices. The of_platform_depopulate() leverages the platform API
for performing the cleanup of these devices.

The platform device resources are managed differently between
of_device_add and platform_device_add, and this asymmetry causes
a kernel oops in platform_device_del during removal of the resources.
Manage the platform device resources similar to platform_device_add
to fix this kernel oops.

Signed-off-by: Suman Anna <s-anna@xxxxxx>
---
drivers/of/device.c | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 46d6c75c1404..fa27c1c71f29 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -50,6 +50,8 @@ EXPORT_SYMBOL(of_dev_put);

int of_device_add(struct platform_device *ofdev)
{
+ int i, ret;
+
BUG_ON(ofdev->dev.of_node == NULL);

/* name and id have to be set so that the platform bus doesn't get
@@ -63,7 +65,41 @@ int of_device_add(struct platform_device *ofdev)
if (!ofdev->dev.parent)
set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));

- return device_add(&ofdev->dev);
+ for (i = 0; i < ofdev->num_resources; i++) {
+ struct resource *p, *r = &ofdev->resource[i];
+
+ if (!r->name)
+ r->name = dev_name(&ofdev->dev);
+
+ p = r->parent;
+ if (!p) {
+ if (resource_type(r) == IORESOURCE_MEM)
+ p = &iomem_resource;
+ else if (resource_type(r) == IORESOURCE_IO)
+ p = &ioport_resource;
+ }
+
+ if (p && insert_resource(p, r)) {
+ dev_err(&ofdev->dev, "failed to claim resource %d\n",
+ i);
+ ret = -EBUSY;
+ goto failed;
+ }
+ }
+
+ ret = device_add(&ofdev->dev);
+ if (ret == 0)
+ return ret;
+
+failed:
+ while (--i >= 0) {
+ struct resource *r = &ofdev->resource[i];
+ unsigned long type = resource_type(r);
+
+ if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
+ release_resource(r);
+ }
+ return ret;
}

int of_device_register(struct platform_device *pdev)
--
2.2.1

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