1 From 389107911744588cce5e06c23a058c9cfb641f33 Mon Sep 17 00:00:00 2001
2 From: Phil Elwell <phil@raspberrypi.com>
3 Date: Tue, 4 Feb 2020 13:03:21 +0000
4 Subject: [PATCH] overlays: dwc2: Increase RX FIFO size
6 The previous version of the dwc2 overlay set the RX FIFO size to
7 256 4-byte words. This sounds large enough for a 1024 byte packet (the
8 largest isochronous high speed packet allowed), but it doesn't take
9 into account some extra space needed by the hardware.
11 Minas Harutyunyan at Synopsys (the source of the DWC OTG design)
12 came up with a more correct value, 301, but since there is spare packet
13 RAM this can be increased to 558 to allow two packets per frame.
15 See: https://github.com/raspberrypi/linux/issues/3447
17 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
19 arch/arm/boot/dts/overlays/dwc2-overlay.dts | 2 +-
20 1 file changed, 1 insertion(+), 1 deletion(-)
22 --- a/arch/arm/boot/dts/overlays/dwc2-overlay.dts
23 +++ b/arch/arm/boot/dts/overlays/dwc2-overlay.dts
25 compatible = "brcm,bcm2835-usb";
27 g-np-tx-fifo-size = <32>;
28 - g-rx-fifo-size = <256>;
29 + g-rx-fifo-size = <558>;
30 g-tx-fifo-size = <512 512 512 512 512 256 256>;