target/linux/bcm27xx/patches-5.4/950-0416-overlays-dwc2-Increase-RX-FIFO-size.patch

   1 From 1257716d9bae9730c43c636046983f5d80c4efc8 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
   5
   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.
  10
  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.
  14
  15 Also update the upstream overlay to match.
  16
  17 See: https://github.com/raspberrypi/linux/issues/3447
  18
  19 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  20 ---
  21  arch/arm/boot/dts/overlays/dwc2-overlay.dts     | 2 +-
  22  arch/arm/boot/dts/overlays/upstream-overlay.dts | 2 +-
  23  2 files changed, 2 insertions(+), 2 deletions(-)
  24
  25 --- a/arch/arm/boot/dts/overlays/dwc2-overlay.dts
  26 +++ b/arch/arm/boot/dts/overlays/dwc2-overlay.dts
  27 @@ -12,7 +12,7 @@
  28                         compatible = "brcm,bcm2835-usb";
  29                         dr_mode = "otg";
  30                         g-np-tx-fifo-size = <32>;
  31 -                       g-rx-fifo-size = <256>;
  32 +                       g-rx-fifo-size = <558>;
  33                         g-tx-fifo-size = <512 512 512 512 512 256 256>;
  34                         status = "okay";
  35                 };
  36 --- a/arch/arm/boot/dts/overlays/upstream-overlay.dts
  37 +++ b/arch/arm/boot/dts/overlays/upstream-overlay.dts
  38 @@ -123,7 +123,7 @@
  39                         compatible = "brcm,bcm2835-usb";
  40                         dr_mode = "otg";
  41                         g-np-tx-fifo-size = <32>;
  42 -                       g-rx-fifo-size = <256>;
  43 +                       g-rx-fifo-size = <558>;
  44                         g-tx-fifo-size = <512 512 512 512 512 256 256>;
  45                         status = "okay";
  46                 };