4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> commit 73f2f5745f18b4ccfe9484deac4e84a1378d19fd upstream. According to the datasheet of R-Car Gen3, the Pn_RAMMAP.Pn_MPKT should be set to one of 8, 16, 32, 64, 512 and 1024. Otherwise, when a gadget driver uses an interrupt endpoint, unexpected behavior happens. So, this patch fixes it. Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/udc/renesas_usb3.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -2048,7 +2048,16 @@ static u32 usb3_calc_ramarea(int ram_siz static u32 usb3_calc_rammap_val(struct renesas_usb3_ep *usb3_ep, const struct usb_endpoint_descriptor *desc) { - return usb3_ep->rammap_val | PN_RAMMAP_MPKT(usb_endpoint_maxp(desc)); + int i; + const u32 max_packet_array[] = {8, 16, 32, 64, 512}; + u32 mpkt = PN_RAMMAP_MPKT(1024); + + for (i = 0; i < ARRAY_SIZE(max_packet_array); i++) { + if (usb_endpoint_maxp(desc) <= max_packet_array[i]) + mpkt = PN_RAMMAP_MPKT(max_packet_array[i]); + } + + return usb3_ep->rammap_val | mpkt; } static int usb3_enable_pipe_n(struct renesas_usb3_ep *usb3_ep,