x86: check for unmask() during deregister_irq()
IRQ handlers for type "IPI" do not have mask or unmask methods.
Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>
diff --git a/kern/arch/x86/trap.c b/kern/arch/x86/trap.c
index b630aba..a365d70 100644
--- a/kern/arch/x86/trap.c
+++ b/kern/arch/x86/trap.c
@@ -843,7 +843,8 @@
/* Ideally, the driver should have told the device to not fire the IRQ
* anymore. If they do, we may get a warn_once. This could be on
* another core, etc. */
- irq_h->mask(irq_h, irq_h->apic_vector);
+ if (irq_h->mask)
+ irq_h->mask(irq_h, irq_h->apic_vector);
synchronize_rcu();
if (irq_h->cleanup)
irq_h->cleanup(irq_h);
