[patch V3 28/35] PCI/MSI: Simplify pci_irq_get_affinity()

[Thomas Gleixner]

On Fri, Dec 17 2021 at 15:30, Nathan Chancellor wrote:
> On Fri, Dec 10, 2021 at 11:19:26PM +0100, Thomas Gleixner wrote:
> I just bisected a boot failure on my AMD test desktop to this patch as
> commit f48235900182 ("PCI/MSI: Simplify pci_irq_get_affinity()") in
> -next. It looks like there is a problem with the NVMe drive after this
> change according to the logs. Given that the hard drive is not getting
> mounted for journald to write logs to, I am not really sure how to get
> them from the machine so I have at least taken a picture of what I see
> on my screen; open to ideas on that front!

Bah. Fix below.

Thanks,

        tglx
---
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 71802410e2ab..9b4910befeda 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -1100,7 +1100,7 @@ EXPORT_SYMBOL(pci_irq_vector);
  */
 const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
 {
-	int irq = pci_irq_vector(dev, nr);
+	int idx, irq = pci_irq_vector(dev, nr);
 	struct msi_desc *desc;
 
 	if (WARN_ON_ONCE(irq <= 0))
@@ -1113,7 +1113,10 @@ const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
 
 	if (WARN_ON_ONCE(!desc->affinity))
 		return NULL;
-	return &desc->affinity[nr].mask;
+
+	/* MSI has a mask array in the descriptor. */
+	idx = dev->msi_enabled ? nr : 0;
+	return &desc->affinity[idx].mask;
 }
 EXPORT_SYMBOL(pci_irq_get_affinity);