Overrun error occurs at UART of i.MX8MQ custom board

[KentarouFujita]

Up to 16 custom boards equipped with i.MX8MQ are connected for RS-485 communication.
We have modified the driver to support the custom baud rate and have successfully communicated at 250000bps.

However, in rare cases, the UART suffers from an overrun error and does not recover.
When this happens, it will not be able to receive at all, but it seems to be able to transmit.

Can anyone tell me what causes the overrun error to occur, or how to recover from it other than rebooting the system when it occurs?

BSP Ver:Linux 5.10.35_2.0.0
imx8mq-evk.dts

/* RS-485 */
&uart3 {
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_uart3>;
	assigned-clocks = <&clk IMX8MQ_CLK_UART3>;
	assigned-clock-parents = <&clk IMX8MQ_CLK_25M>;
	uart-has-rtscts;
	rts-gpios = <&gpio5 8 GPIO_ACTIVE_HIGH>;
	linux,rs485-enabled-at-boot-time;
	status = "okay";
};

[KentarouFujita · Accepted solution]

This case was due to memory corruption caused by an inadequate DRAM configuration. The problem has now been resolved. This ticket has served its purpose and is closed.

[Juan-Rodarte]

Hi Kentarou,

You can upgrade to a newer BSP.

Regards