On 15 August 2016 at 09:12, Liang, Kan <kan.li...@intel.com> wrote:
>
>
>> > diff --git a/arch/x86/events/intel/uncore_snbep.c
>> > b/arch/x86/events/intel/uncore_snbep.c
>> > index 3719af5..55a081e 100644
>> > --- a/arch/x86/events/intel/uncore_snbep.c
>> > +++ b/arch/x86/events/intel/uncore_snbep.c
>> > +
>> > +static int skx_count_chabox(void)
>> > +{
>> > + struct pci_dev *chabox_dev = NULL;
>> > + int bus, count = 0;
>> > +
>> > + while (1) {
>> > + chabox_dev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x208d,
>> chabox_dev);
>> > + if (!chabox_dev)
>> > + break;
>> > + if (count == 0)
>> > + bus = chabox_dev->bus->number;
>> > + if (bus != chabox_dev->bus->number)
>> > + break;
>> > + count++;
>> > + }
>> > +
>> > + pci_dev_put(chabox_dev);
>> > + return count;
>> > +}
>>
>> Kan, do we not need to call pci_dev_put() each time we call
>> pci_get_device()?
>
> The pci_get_device will always decrease the reference count for chabox_dev, if
> it is not NULL.
> So I think it's OK to only pci_dev_put it at last.
>
Yup, you are right. I was not aware that pci_dev_put() gets called
automatically when pci_dev argument is not NULL.
Thanks for the info.
--
Nilay
