The previous version of the dwc2 overlay set the RX FIFO size to 256 4-byte words. This sounds large enough for a 1024 byte packet (the largest isochronous high speed packet allowed), but it doesn't take into account some extra space needed by the hardware. Minas Harutyunyan at Synopsys (the source of the DWC OTG design) came up with a more correct value, 301, but since there is spare packet RAM this can be increased to 558 to allow two packets per frame. See: https://github.com/raspberrypi/linux/issues/3447 Signed-off-by: Phil Elwell <phil@xxxxxxxxxxxxxxx> Signed-off-by: Pavel Hofman <pavel.hofman@xxxxxxxxxxx> --- arch/arm/boot/dts/bcm283x-rpi-usb-otg.dtsi | 2 +- arch/arm/boot/dts/bcm283x-rpi-usb-peripheral.dtsi | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/boot/dts/bcm283x-rpi-usb-otg.dtsi b/arch/arm/boot/dts/bcm283x-rpi-usb-otg.dtsi index e2fd961..20322de 100644 --- a/arch/arm/boot/dts/bcm283x-rpi-usb-otg.dtsi +++ b/arch/arm/boot/dts/bcm283x-rpi-usb-otg.dtsi @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 &usb { dr_mode = "otg"; - g-rx-fifo-size = <256>; + g-rx-fifo-size = <558>; g-np-tx-fifo-size = <32>; /* * According to dwc2 the sum of all device EP diff --git a/arch/arm/boot/dts/bcm283x-rpi-usb-peripheral.dtsi b/arch/arm/boot/dts/bcm283x-rpi-usb-peripheral.dtsi index 0ff0e9e..1409d1b 100644 --- a/arch/arm/boot/dts/bcm283x-rpi-usb-peripheral.dtsi +++ b/arch/arm/boot/dts/bcm283x-rpi-usb-peripheral.dtsi @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 &usb { dr_mode = "peripheral"; - g-rx-fifo-size = <256>; + g-rx-fifo-size = <558>; g-np-tx-fifo-size = <32>; g-tx-fifo-size = <256 256 512 512 512 768 768>; }; -- 1.9.1
