On Wed, Jan 7, 2015 at 11:30 AM, Suman Anna <s-anna@xxxxxx> wrote:
> 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.
This is a known issue and has been attempted to be fixed before (I
believe there is a revert in mainline). The problem is there are known
devicetrees which have overlapping resources and they will break with
your change.
Rob
>
> 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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