Re: [PATCH v3] PCI: Check for PCIe downtraining conditions

[Tal Gilboa]

On 7/19/2018 6:49 PM, Alex G. wrote:
> On 07/18/2018 08:38 AM, Tal Gilboa wrote:
> > On 7/16/2018 5:17 PM, Bjorn Helgaas wrote:
> > > [+cc maintainers of drivers that already use pcie_print_link_status()
> > > and GPU folks]
> [snip]
> > > > +ÂÂÂ /* Multi-function PCIe share the same link/status. */
> > > > +ÂÂÂ if ((PCI_FUNC(dev->devfn) != 0) || dev->is_virtfn)
> > > > +ÂÂÂÂÂÂÂ return;
> > > > +
> > > > +ÂÂÂ pcie_print_link_status(dev);
> > > > +}
> >
> > Is this function called by default for every PCIe device? What about 
> > VFs? We make an exception for them on our driver since a VF doesn't 
> > have access to the needed information in order to provide a meaningful 
> > message.
>
> I'm assuming VF means virtual function. pcie_print_link_status() doesn't 
> care if it's passed a virtual function. It will try to do its job. 
> That's why I bail out three lines above, with 'dev->is_virtfn' check.
>
> Alex

That's the point - we don't want to call pcie_print_link_status() for 
virtual functions. We make the distinction in our driver. If you want to 
change the code to call this function by default it shouldn't affect the 
current usage.