diff --git a/drivers/ata/pata_it8213.c b/drivers/ata/pata_it8213.c
index 36d1f61..092af53 100644
--- a/drivers/ata/pata_it8213.c
+++ b/drivers/ata/pata_it8213.c
@@ -112,13 +112,13 @@
 	} else {
 		u8 slave_data;
 
-		idetm_data &= 0xCC0F;
+		idetm_data &= 0xFF0F;
 		idetm_data |= (control << 4);
 
 		/* Slave timing in separate register */
 		pci_read_config_byte(dev, 0x44, &slave_data);
 		slave_data &= 0xF0;
-		slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << 4;
+		slave_data |= (timings[pio][0] << 2) | timings[pio][1];
 		pci_write_config_byte(dev, 0x44, slave_data);
 	}