On 2014/5/30 10:07, Bjorn Helgaas wrote:
> 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.
Hi Bjorn,
I didn't convert it to void because the device_attach() has a __must_check prefix
which need a retval to avoid compiler warning. But as you mentioned, maybe this will
make people confuse. I will rework it and squash them into a single one.
Thanks!
Yijing.
>
>> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
>> ---
>> 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
>>
>>
>
>
--
Thanks!
Yijing
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