Re: [PATCH 15/16 v6] PCI: document the SR-IOV sysfs entries

From: Greg KH
Date: Thu Nov 06 2008 - 22:23:20 EST


On Fri, Nov 07, 2008 at 11:01:29AM +0800, Zhao, Yu wrote:
> Greg KH wrote:
>> On Wed, Nov 05, 2008 at 08:33:18PM -0800, Greg KH wrote:
>>> On Wed, Oct 22, 2008 at 04:45:15PM +0800, Yu Zhao wrote:
>>>> Documentation/ABI/testing/sysfs-bus-pci | 33
>>>> +++++++++++++++++++++++++++++++
>>>> 1 files changed, 33 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/Documentation/ABI/testing/sysfs-bus-pci
>>>> b/Documentation/ABI/testing/sysfs-bus-pci
>>>> index ceddcff..41cce8f 100644
>>>> --- a/Documentation/ABI/testing/sysfs-bus-pci
>>>> +++ b/Documentation/ABI/testing/sysfs-bus-pci
>>>> @@ -9,3 +9,36 @@ Description:
>>>> that some devices may have malformatted data. If the
>>>> underlying VPD has a writable section then the
>>>> corresponding section of this file will be writable.
>>>> +
>>>> +What: /sys/bus/pci/devices/.../iov/enable
>>> Are you sure this is still the correct location with your change to
>>> struct device?
>> Nevermind, this is correct.
>> But the bigger problem is that userspace doesn't know when these
>> attributes show up. So tools like udev and HAL and others can't look
>> for them as they never get notified, and they don't even know if they
>> should be looking for them or not.
>> Is there any way to tie these attributes to the "main" pci device so
>> that they get created before the device is announced to the world?
>> Doing that would solve this issue.
>> thanks,
>> greg k-h
>
> Currently PCI subsystem has /sys/.../{vendor,device,...} bundled to the
> main PCI device (I suppose this means the entries are created by
> 'device_add')
>
> And after the PCI device is announced,
> /sys/.../{config,resourceX,rom,vpd,iov,...} get created depending on if
> these features are supported.

And that's a bug. Let's not continue to make the same bug here as well.

> Making dynamic entries tie to the main PCI device would require PCI
> subsystem to allocate different 'bus_type' for the devices, right?

No, it would just mean they need to be all added before the device is
fully registered with the driver core.

thanks,

greg k-h
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