patch "usb: gadget: udc: renesas_usb3: fix Pn_RAMMAP.Pn_MPKT value" added to usb-linus

This is a note to let you know that I've just added the patch titled

usb: gadget: udc: renesas_usb3: fix Pn_RAMMAP.Pn_MPKT value

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From: Yoshihiro Shimoda <[email protected]>
Date: Mon, 25 Sep 2017 17:01:24 +0900
Subject: usb: gadget: udc: renesas_usb3: fix Pn_RAMMAP.Pn_MPKT value

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.

---
 drivers/usb/gadget/udc/renesas_usb3.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

index 555c105e82df..7e0c53492356 100644
@@ -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,

2.14.1