Re: [Xen-devel] [PATCH V3 1/2] Drivers/PCI: Export pcie_has_flr() interface

Govinda Tatti
2017-12-15T20:08:12Z

Thanks Bjorn for your response. Please see below for my comments.
>> So, we should consider one of these options.
>>
>> - set PCI_DEV_FLAGS_NO_FLR_RESET if it is not supported.
>> - pcie_flr() should return if it is not supported
>>
>> If we modify pcie_flr() to return error codes, then we need to modify
>> all existing modules that are calling this function.
> Yes, of course.
>
>> Please let me know your preference, so that I can move accordingly. Thanks.
> I think Christoph volunteered to do some restructuring, but I don't
> know his timeframe. If you can, I would probably wait for that
> because there's so much overlap here.
OK.
>
> The other paths that use PCI_EXP_DEVCTL_BCR_FLR are definitely issues
> and should be fixed, but again should wait for the revised pcie_flr()
> interface. And if they're not actually required for your Xen issue,
> they sound like "nice to have" cleanups that will not gate your Xen
> fixes. I added this to my ever-growing list of cleanups to do.
For now, I am planning to use existing pcie_flr() after checking FLR
capability inside Xenpciback driver (like other existing pcie_flr()
usage). We will switch to revised pcie_flr() once it is available.

Cheers
GOVINDA