--- ata-chipset.c	2008-07-23 21:10:54.700145967 -0500
+++ ata-chipset.c.k2	2008-07-23 21:10:49.431251177 -0500
@@ -50,6 +50,12 @@
 #include <dev/ata/ata-pci.h>
 #include <ata_if.h>
 
+#ifdef __powerpc__
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_pci.h>
+#include <powerpc/ofw/ofw_pci.h>
+#endif
+
 /* local prototypes */
 /* ata-chipset.c */
 static int ata_generic_chipinit(device_t dev);
@@ -4687,6 +4693,29 @@
 {
     struct ata_pci_controller *ctlr = device_get_softc(dev);
 
+#ifdef __powerpc__
+    /*
+     * The K2 controller in Apple G5s does not have its interrupt property
+     * set, and does not accept writes to PCI config space like most other
+     * devices. Solve with sledgehammer.
+     */
+
+    int status;
+    u_long startp, countp;
+
+    status = bus_get_resource(dev, SYS_RES_IRQ, 0, &startp, &countp);
+    if (status == ENOENT) {
+	int irq;
+	phandle_t node;
+
+	node = ofw_pci_find_node(dev);
+	OF_getprop(node, "interrupts", &irq, sizeof(irq));
+
+	bus_set_resource(dev, SYS_RES_IRQ, 0, irq, 1);
+    }
+#endif
+
+
     if (ata_setup_interrupt(dev))
 	return ENXIO;