This controller can control "Transaction Translators", but
the hcd->has_tt is not set.
Since the commit 
d199c96d41d80a567493e12b8e96ea056a1350c1
("USB: prevent buggy from crashing the USB stack") has checked it,
the driver could not work the low/full speed device.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
 
        INIT_LIST_HEAD(&r8a66597->child_device);
 
        hcd->rsrc_start = res->start;
+       hcd->has_tt = 1;
 
        ret = usb_add_hcd(hcd, irq, IRQF_DISABLED | irq_trigger);
        if (ret != 0) {