Re: [PATCH 1/3] PCI: remove the unnecssary checking for pci_bus_add_device

[Bjorn Helgaas <bhelgaas@google.com>]

On Thu, May 29, 2014 at 03:01:04PM +0800, Yijing Wang wrote:
> Kernel will WARN_ON(retval < 0) if device_attach() fail with
> error in pci_bus_add_device(). currently, all the kernel code
> to check pci_bus_add_device() return value only for printing
> warning message, no other actions. So we can remove the
> unnecessary checking codes.

If we remove all the checks of the return value, why wouldn't we convert it
to a void function?  If we keep the return value, it seems like we're
saying "this function could fail someday," but we removing all the code
that would actually *check* for that failure.

If you convert it to void, please just squash them all into a single patch.

> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> ---
>  drivers/pci/bus.c   |    6 +-----
>  drivers/pci/iov.c   |    2 +-
>  include/linux/pci.h |    2 +-
>  3 files changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index ba2bf55..f0efbee 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -266,16 +266,12 @@ void pci_bus_add_devices(const struct pci_bus *bus)
>  {
>  	struct pci_dev *dev;
>  	struct pci_bus *child;
> -	int retval;
>  
>  	list_for_each_entry(dev, &bus->devices, bus_list) {
>  		/* Skip already-added devices */
>  		if (dev->is_added)
>  			continue;
> -		retval = pci_bus_add_device(dev);
> -		if (retval)
> -			dev_err(&dev->dev, "Error adding device (%d)\n",
> -				retval);
> +		pci_bus_add_device(dev);
>  	}
>  
>  	list_for_each_entry(dev, &bus->devices, bus_list) {
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index de7a747..cb6f247 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -106,7 +106,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
>  	pci_device_add(virtfn, virtfn->bus);
>  	mutex_unlock(&iov->dev->sriov->lock);
>  
> -	rc = pci_bus_add_device(virtfn);
> +	pci_bus_add_device(virtfn);
>  	sprintf(buf, "virtfn%u", id);
>  	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
>  	if (rc)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 65f22e8..3c4c0cf 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -781,7 +781,7 @@ int pci_scan_slot(struct pci_bus *bus, int devfn);
>  struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn);
>  void pci_device_add(struct pci_dev *dev, struct pci_bus *bus);
>  unsigned int pci_scan_child_bus(struct pci_bus *bus);
> -int __must_check pci_bus_add_device(struct pci_dev *dev);
> +int pci_bus_add_device(struct pci_dev *dev);
>  void pci_read_bridge_bases(struct pci_bus *child);
>  struct resource *pci_find_parent_resource(const struct pci_dev *dev,
>  					  struct resource *res);
> -- 
> 1.7.1
> 
>