Index: sys/arm/arm/gic.c
===================================================================
--- sys/arm/arm/gic.c
+++ sys/arm/arm/gic.c
@@ -1438,18 +1438,18 @@
 		found = true;
 
 		/* Check this range is valid */
-		for (end_irq = irq; end_irq != irq + count - 1; end_irq++) {
-			/* No free interrupts */
-			if (end_irq == sc->sc_spi_end) {
+		for (end_irq = irq; end_irq < irq + count; end_irq++) {
+			KASSERT((psc->gic_irqs[end_irq].gi_flags & GI_FLAG_MSI)!= 0,
+			    ("%s: Non-MSI interrupt found", __func__));
+
+			/* Range does not fit */
+			if (end_irq >= sc->sc_spi_end) {
 				found = false;
 				break;
 			}
 
-			KASSERT((psc->gic_irqs[irq].gi_flags & GI_FLAG_MSI)!= 0,
-			    ("%s: Non-MSI interrupt found", __func__));
-
 			/* This is already used */
-			if ((psc->gic_irqs[irq].gi_flags & GI_FLAG_MSI_USED) ==
+			if ((psc->gic_irqs[end_irq].gi_flags & GI_FLAG_MSI_USED) ==
 			    GI_FLAG_MSI_USED) {
 				found = false;
 				break;