diff --git a/drivers/ide/hpt366.c b/drivers/ide/hpt366.c
index c613ae1..58c51cd 100644
--- a/drivers/ide/hpt366.c
+++ b/drivers/ide/hpt366.c
@@ -838,7 +838,7 @@
 
 static void hpt3xxn_rw_disk(ide_drive_t *drive, struct request *rq)
 {
-	hpt3xxn_set_clock(drive->hwif, rq_data_dir(rq) ? 0x23 : 0x21);
+	hpt3xxn_set_clock(drive->hwif, rq_data_dir(rq) ? 0x21 : 0x23);
 }
 
 /**