diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 026439e..c750105 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -882,7 +882,7 @@
 	/* Filter out DMA modes if the device has been configured by
 	   the BIOS as PIO only */
 
-	if (adev->link->ap->ioaddr.bmdma_addr == 0)
+	if (adev->link->ap->ioaddr.bmdma_addr == NULL)
 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
 	return xfer_mask;
 }