ARM: dts: Disable DMA support on the BK4 vf610 device's fsl_lpuart

This change disables the DMA support (RX/TX) on the NXP's fsl_lpuart
driver - the PIO mode is used instead. This change is necessary for better
robustness of BK4's device use cases with many potentially interrupted
short serial transfers.

Without it the driver hangs when some distortion happens on UART lines.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

diff --git a/arch/arm/boot/dts/vf610-bk4.dts b/arch/arm/boot/dts/vf610-bk4.dts
index 0f3870d3b0990e7f07caf2be5a4a0a47ece86366..830c85476b3d8a650424afb042e50f832ebbe619 100644 (file)
--- a/arch/arm/boot/dts/vf610-bk4.dts
+++ b/arch/arm/boot/dts/vf610-bk4.dts
@@ -259,24 +259,28 @@
 &uart0 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_uart0>;
+       /delete-property/dma-names;
        status = "okay";
 };
 
 &uart1 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_uart1>;
+       /delete-property/dma-names;
        status = "okay";
 };
 
 &uart2 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_uart2>;
+       /delete-property/dma-names;
        status = "okay";
 };
 
 &uart3 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_uart3>;
+       /delete-property/dma-names;
        status = "okay";
 };