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")
Cc: <sta...@vger.kernel.org> # v4.5+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda...@renesas.com>
---
drivers/usb/gadget/udc/renesas_usb3.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/udc/renesas_usb3.c
b/drivers/usb/gadget/udc/renesas_usb3.c
index 555c105..7e0c534 100644
--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -2054,7 +2054,16 @@ static u32 usb3_calc_ramarea(int ram_size)
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,
--
1.9.1
