[PATCH v2 2/2] arm64: dts: imx8: fix USB 3.0 Gadget Failure in QM & QXPB0 at super speed

[Frank Li]

Resolve USB 3.0 gadget failure for QM and QXPB0 in super speed mode with
single IN and OUT endpoints, like mass storage devices, due to incorrect
ACTUAL_MEM_SIZE in ep_cap2 (32k instead of actual 18k). Implement dt
property cdns,on-chip-buff-size to override ep_cap2 and set it to 18k for
imx8QM and imx8QXP chips. No adverse effects for 8QXP C0.

Fixes: dce49449e04f ("usb: cdns3: allocate TX FIFO size according to composite EP number")
Signed-off-by: Frank Li <Frank.Li at nxp.com>
---
change from v1 to v2
- fixes warning from check-patch
- update dt-binding doc

 arch/arm64/boot/dts/freescale/imx8-ss-conn.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8-ss-conn.dtsi b/arch/arm64/boot/dts/freescale/imx8-ss-conn.dtsi
index b32c2e199c16..030c273c8be4 100644
--- a/arch/arm64/boot/dts/freescale/imx8-ss-conn.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8-ss-conn.dtsi
@@ -171,6 +171,7 @@ usbotg3_cdns3: usb at 5b120000 {
 			interrupt-names = "host", "peripheral", "otg", "wakeup";
 			phys = <&usb3_phy>;
 			phy-names = "cdns3,usb3-phy";
+			cdns,on-chip-buff-size = /bits/ 16 <18>;
 			status = "disabled";
 		};
 	};
-- 
2.34.1