diff --git a/drivers/ide/ppc/pmac.c b/drivers/ide/ppc/pmac.c
index b43457e34311..cfbe5690ca88 100644
--- a/drivers/ide/ppc/pmac.c
+++ b/drivers/ide/ppc/pmac.c
@@ -916,14 +916,15 @@ static int pmac_ide_tune_chipset(ide_drive_t *drive, const u8 speed)
 	int unit = (drive->select.b.unit & 0x01);
 	int ret = 0;
 	pmac_ide_hwif_t* pmif = (pmac_ide_hwif_t *)HWIF(drive)->hwif_data;
-	u32 *timings, *timings2;
+	u32 *timings, *timings2, tl[2];
 
-	if (pmif == NULL)
-		return 1;
-		
 	timings = &pmif->timings[unit];
 	timings2 = &pmif->timings[unit+2];
-	
+
+	/* Copy timings to local image */
+	tl[0] = *timings;
+	tl[1] = *timings2;
+
 	switch(speed) {
 #ifdef CONFIG_BLK_DEV_IDEDMA_PMAC
 		case XFER_UDMA_6:
@@ -934,19 +935,19 @@ static int pmac_ide_tune_chipset(ide_drive_t *drive, const u8 speed)
 		case XFER_UDMA_1:
 		case XFER_UDMA_0:
 			if (pmif->kind == controller_kl_ata4)
-				ret = set_timings_udma_ata4(timings, speed);
+				ret = set_timings_udma_ata4(&tl[0], speed);
 			else if (pmif->kind == controller_un_ata6
 				 || pmif->kind == controller_k2_ata6)
-				ret = set_timings_udma_ata6(timings, timings2, speed);
+				ret = set_timings_udma_ata6(&tl[0], &tl[1], speed);
 			else if (pmif->kind == controller_sh_ata6)
-				ret = set_timings_udma_shasta(timings, timings2, speed);
+				ret = set_timings_udma_shasta(&tl[0], &tl[1], speed);
 			else
-				ret = 1;		
+				ret = 1;
 			break;
 		case XFER_MW_DMA_2:
 		case XFER_MW_DMA_1:
 		case XFER_MW_DMA_0:
-			ret = set_timings_mdma(drive, pmif->kind, timings, timings2, speed, 0);
+			ret = set_timings_mdma(drive, pmif->kind, &tl[0], &tl[1], speed, 0);
 			break;
 		case XFER_SW_DMA_2:
 		case XFER_SW_DMA_1:
@@ -962,7 +963,11 @@ static int pmac_ide_tune_chipset(ide_drive_t *drive, const u8 speed)
 	ret = pmac_ide_do_setfeature(drive, speed);
 	if (ret)
 		return ret;
-		
+
+	/* Apply timings to controller */
+	*timings = tl[0];
+	*timings2 = tl[1];
+
 	pmac_ide_do_update_timings(drive);	
 
 	return 0;