Re: [PATCHv2] PCI: vmd: Use affinity to chain child device interrupts

[Keith Busch <keith.busch@intel.com>]

On Tue, Mar 13, 2018 at 02:08:40PM -0600, Keith Busch wrote:
> On Tue, Mar 13, 2018 at 05:10:39PM +0000, Lorenzo Pieralisi wrote:
> > On Tue, Feb 06, 2018 at 01:22:25PM -0700, Keith Busch wrote:
> > > @@ -233,9 +266,11 @@ static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
> > >  	struct pci_dev *pdev = to_pci_dev(dev);
> > >  	struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
> > >  
> > > -	if (nvec > vmd->msix_count)
> > > +	if (nvec > vmd->msix_count) {
> > > +		if (vmd->msix_count > 1)
> > > +			return vmd->msix_count - 1;
> > >  		return vmd->msix_count;
> > 
> > I am about to apply this patch but I do not understand what's this hunk
> > is there for, to me vmd_msi_prepare() should just return an error in
> > this code path unless I am getting this wrong.
> 
> The change above is fixing an off-by-one.

And since you brought my attention to it, I see the 'if' is off by one.
Let me prepare a v3, and I've one other minor optimization to add as
well.

Thanks,
Keith