Re: [PATCH 06/23] PCI: rescan with bus or bridge using callback method too

Yinghai Lu
2012-03-09T06:53:23Z

On Thu, Mar 8, 2012 at 4:56 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> On Tue, Mar 6, 2012 at 12:13 AM, Yinghai Lu <yinghai@kernel.org> wrote:
>> Just like removal.
>>
>> Because We could add new bus under the bridges...
>>
>> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
>> ---
>>  drivers/pci/pci-sysfs.c |   43 +++++++++++++++++++++++++++++++------------
>>  1 files changed, 31 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
>> index 2049b2f..1794508 100644
>> --- a/drivers/pci/pci-sysfs.c
>> +++ b/drivers/pci/pci-sysfs.c
>> @@ -325,21 +325,31 @@ dev_rescan_store(struct device *dev, struct device_attribute *attr,
>>        return count;
>>  }
>>
>> +static void bridge_rescan_callback(struct device *dev)
>> +{
>> +       struct pci_dev *pdev = to_pci_dev(dev);
>> +
>> +       mutex_lock(&pci_remove_rescan_mutex);
>> +       pci_rescan_bus_bridge_resize(pdev);
>> +       mutex_unlock(&pci_remove_rescan_mutex);
>> +}
>> +
>>  static ssize_t
>>  dev_bridge_rescan_store(struct device *dev, struct device_attribute *attr,
>>                 const char *buf, size_t count)
>>  {
>> +       int ret = 0;
>>        unsigned long val;
>> -       struct pci_dev *pdev = to_pci_dev(dev);
>>
>>        if (kstrtoul(buf, 0, &val) < 0)
>>                return -EINVAL;
>>
>> -       if (val) {
>> -               mutex_lock(&pci_remove_rescan_mutex);
>> -               pci_rescan_bus_bridge_resize(pdev);
>> -               mutex_unlock(&pci_remove_rescan_mutex);
>> -       }
>> +       if (val)
>> +               ret = device_schedule_callback(dev, bridge_rescan_callback);
>> +
>> +       if (ret)
>> +               count = ret;
>> +
>>        return count;
>
> I see that you copied this style from remove_store(), but it's ugly
> and hard to follow.  I think this would be more readable:
>
>    if (!val)
>        return count;
>
>    err = device_schedule_callback(dev, bridge_rescan_callback);
>    if (err)
>        return err;
>
>    return count;
>

like

if (!val)
return count;

ret = device_schedule_callback(dev, bus_rescan_callback);

if (ret)
return ret;

return count;

that will have three return instead of one.

both should be ok.

Yinghai