Re: [PATCH] Driver core: Don't ignore error returns from probing

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Thu, 5 Oct 2006 17:03:24 -0400 (EDT),
Alan Stern <stern@rowland.harvard.edu> wrote:

> Index: 18g20/drivers/base/bus.c
> ===================================================================
> --- 18g20.orig/drivers/base/bus.c
> +++ 18g20/drivers/base/bus.c
> @@ -453,8 +453,10 @@ void bus_remove_device(struct device * d
>  		remove_deprecated_bus_links(dev);
>  		sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
>  		device_remove_attrs(dev->bus, dev);
> -		dev->is_registered = 0;
> -		klist_del(&dev->knode_bus);
> +		if (dev->is_registered) {
> +			dev->is_registered = 0;
> +			klist_del(&dev->knode_bus);
> +		}
>  		pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);
>  		device_release_driver(dev);
>  		put_bus(dev->bus);
> Index: 18g20/drivers/base/core.c
> ===================================================================
> --- 18g20.orig/drivers/base/core.c
> +++ 18g20/drivers/base/core.c
> @@ -485,7 +485,8 @@ int device_add(struct device *dev)
>  	if ((error = bus_add_device(dev)))
>  		goto BusError;
>  	kobject_uevent(&dev->kobj, KOBJ_ADD);
> -	bus_attach_device(dev);
> +	if ((error = bus_attach_device(dev)))
> +		goto AttachError;
>  	if (parent)
>  		klist_add_tail(&dev->knode_parent, &parent->klist_children);
>  
> @@ -504,6 +505,8 @@ int device_add(struct device *dev)
>   	kfree(class_name);
>  	put_device(dev);
>  	return error;
> + AttachError:
> +	bus_remove_device(dev);
>   BusError:
>  	device_pm_remove(dev);
>   PMError:

Hm, I don't think we should call device_release_driver if
bus_attach_device failed (and I think calling bus_remove_device if
bus_attach_device failed is unintuitive). I did a patch that added a
function which undid just the things bus_add_device did (here:
http://marc.theaimsgroup.com/?l=linux-kernel&m=115816560424389&w=2),
which unfortunately got lost somewhere... (I'll rebase and resend.)

-- 
Cornelia Huck
Linux for zSeries Developer
Tel.: +49-7031-16-4837, Mail: cornelia.huck@de.ibm.com