[PATCH v1 2/2] ARM: dts: at91: gardena-smart-gateway: Use DMA for USART3

[ezra at easyb.ch]

From: Ezra Buehler <ezra.buehler at husqvarnagroup.com>

The AT91SAM9G25-based GARDENA smart Gateway uses USART3 (ttyS1) to
communicate (over PPP, at 115200 baud) with the radio module.

We have been experiencing packet loss and seeing errors on the ppp0
interface. Enabling DMA for the serial interface resolves the issues.

Co-Developed-by: Michael Zimmermann <michael.zimmermann at grandcentrix.net>
Signed-off-by: Michael Zimmermann <michael.zimmermann at grandcentrix.net>
Signed-off-by: Ezra Buehler <ezra.buehler at husqvarnagroup.com>
---
 .../boot/dts/microchip/at91sam9g25-gardena-smart-gateway.dts    | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/microchip/at91sam9g25-gardena-smart-gateway.dts b/arch/arm/boot/dts/microchip/at91sam9g25-gardena-smart-gateway.dts
index 92f2c05c873f..af70eb8a3a02 100644
--- a/arch/arm/boot/dts/microchip/at91sam9g25-gardena-smart-gateway.dts
+++ b/arch/arm/boot/dts/microchip/at91sam9g25-gardena-smart-gateway.dts
@@ -121,6 +121,8 @@ &usart2 {
 };
 
 &usart3 {
+	atmel,use-dma-rx;
+	atmel,use-dma-tx;
 	status = "okay";
 
 	pinctrl-0 = <&pinctrl_usart3
-- 
2.39.2