1 files changed, 14 insertions, 1 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 29290f554e79..40a4aa3f4061 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1070,6 +1070,11 @@ static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
         }
 
         if (flags & IOAPIC_MAP_ALLOC) {
+                /* special handling for legacy IRQs */
+                if (irq < nr_legacy_irqs() && info->count == 1 &&
+                    mp_irqdomain_map(domain, irq, pin) != 0)
+                        irq = -1;
+
                 if (irq > 0)
                         info->count++;
                 else if (info->count == 0)
@@ -3896,7 +3901,15 @@ int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq,
                         info->polarity = 1;
                 }
                 info->node = NUMA_NO_NODE;
-                info->set = 1;
+
+                /*
+                 * setup_IO_APIC_irqs() programs all legacy IRQs with default
+                 * trigger and polarity attributes. Don't set the flag for that
+                 * case so the first legacy IRQ user could reprogram the pin
+                 * with real trigger and polarity attributes.
+                 */
+                if (virq >= nr_legacy_irqs() || info->count)
+                        info->set = 1;
         }
         set_io_apic_irq_attr(&attr, ioapic, hwirq, info->trigger,
                              info->polarity);