diff --git a/drivers/ide/ppc/pmac.c b/drivers/ide/ppc/pmac.c
index e68e33b..7c3a84f 100644
--- a/drivers/ide/ppc/pmac.c
+++ b/drivers/ide/ppc/pmac.c
@@ -495,6 +495,13 @@
 				     + IDE_TIMING_CONFIG));
 }
 
+static void pmac_exec_command(ide_hwif_t *hwif, u8 cmd)
+{
+	writeb(cmd, (void __iomem *)hwif->io_ports.command_addr);
+	(void)readl((void __iomem *)(hwif->io_ports.data_addr
+				     + IDE_TIMING_CONFIG));
+}
+
 /*
  * Old tuning functions (called on hdparm -p), sets up drive PIO timings
  */
@@ -1092,6 +1099,8 @@
 	if (hwif == NULL)
 		return -ENOENT;
 
+	hwif->exec_command = pmac_exec_command;
+
 	/* Setup MMIO ops */
 	default_hwif_mmiops(hwif);
        	hwif->OUTBSYNC = pmac_outbsync;