pci_msix_alloc_irq_at() affinity

[Shay Drori]

Hello Thomas

I did some testing with pci_msix_alloc_irq_at() and I noticed that the
affinity provided, via “struct irq_affinity_desc *af_desc”, doesn’t have
any affect.

After some digging, I found out that irq_setup_affinity(), which is
called by request_irq(), is setting the affinity as all the CPUs online,
ignoring the affinity provided in pci_msix_alloc_irq_at().
Is this on purpose or a bug?

P.S. The bellow diff honors the affinity provided in
pci_msix_alloc_irq_at()

--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -530,6 +530,7 @@ static int alloc_descs(unsigned int start, unsigned 
int cnt, int node,
                                flags = IRQD_AFFINITY_MANAGED |
                                        IRQD_MANAGED_SHUTDOWN;
                        }
+                 flags |= IRQD_AFFINITY_SET;
                        mask = &affinity->mask;
                        node = cpu_to_node(cpumask_first(mask));
                        affinity++;

thanks
Shay Drori