Re: [PATCH] cciss: return 0 from driver probe function on success, not 1

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 01 Nov 2013 14:06:45 +0100 Tomas Henzl <thenzl@redhat.com> wrote:

> The problem in kernel is that the error handling in local_pci_probe
> and  in __pci_device_probe is different for ret values > 0,
> so we should fix it somewhere so it is in sync.
> The documentation states that the probe function should return zero on success
> so what about this -
> 
> This would bring the handling to sync
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 98f7b9b..200a071 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -317,8 +317,6 @@ __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
>  		id = pci_match_device(drv, pci_dev);
>  		if (id)
>  			error = pci_call_probe(drv, pci_dev, id);
> -		if (error >= 0)
> -			error = 0;
>  	}
>  	return error;
>  }

ah, there it is.

This change would turn semi-kaput drivers into kaput-kaput drivers.  It
would be better to add a runtime warning here so those drivers get
fixed.  Such a warning would need to reliably identify the offending
probe function so a simple WARN_ON() wouldn't be sufficient.