1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/ide/pci/alim15x3.c b/drivers/ide/pci/alim15x3.c
index 946a12746cb5..26c27d946c67 100644
--- a/drivers/ide/pci/alim15x3.c
+++ b/drivers/ide/pci/alim15x3.c
@@ -783,8 +783,17 @@ static void __devinit init_hwif_common_ali15x3 (ide_hwif_t *hwif)
 
         hwif->atapi_dma = 1;
 
-        if (m5229_revision > 0x20)
-                hwif->ultra_mask = 0x7f;
+        if (m5229_revision <= 0x20)
+                hwif->ultra_mask = 0x00; /* no udma */
+        else if (m5229_revision < 0xC2)
+                hwif->ultra_mask = 0x07; /* udma0-2 */
+        else if (m5229_revision == 0xC2 || m5229_revision == 0xC3)
+                hwif->ultra_mask = 0x1f; /* udma0-4 */
+        else if (m5229_revision == 0xC4)
+                hwif->ultra_mask = 0x3f; /* udma0-5 */
+        else
+                hwif->ultra_mask = 0x7f; /* udma0-6 */
+
         hwif->mwdma_mask = 0x07;
         hwif->swdma_mask = 0x07;