diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index d4b298eb5efe..30f27585a7d3 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1826,7 +1826,7 @@ static ide_startstop_t cdrom_write_intr(ide_drive_t *drive)
 	}
 
 	/* Read the interrupt reason and the transfer length. */
-	ireason = HWIF(drive)->INB(IDE_IREASON_REG);
+	ireason = HWIF(drive)->INB(IDE_IREASON_REG) & 0x3;
 	lowcyl  = HWIF(drive)->INB(IDE_BCOUNTL_REG);
 	highcyl = HWIF(drive)->INB(IDE_BCOUNTH_REG);