Re: [PATCH v1 3/3] arm64: dts: imx8mp-var-smarc: Add support for Variscite Echo board

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] arm64: dts: imx8mp-var-smarc-echo: missing uart-has-rtscts on
  uart1
--

commit 2120b57aa36b03b0bbf74c4c8b3c605d83172578
Author: Stefano Radaelli <stefano.r@variscite.com>

arm64: dts: imx8mp-var-smarc: Add support for Variscite Echo board

This commit adds a device tree for the Variscite Echo carrier board paired
with the VAR-SMARC-MX8M-PLUS system on module.

Link: https://variscite.com/carrier-boards/echo-board/

> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-var-smarc-echo.dts b/arch/arm64/boot/dts/freescale/imx8mp-var-smarc-echo.dts
> new file mode 100644
> index 0000000000000..341d8af16cd82
> --- /dev/null
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-var-smarc-echo.dts

[ ... ]

> +/* Header */
> +&uart1 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pinctrl_uart1>;
> +	status = "okay";
> +};

[Severity: Medium]
Should the uart1 node include uart-has-rtscts?

pinctrl_uart1 muxes MX8MP_IOMUXC_UART3_RXD__UART1_DCE_CTS and
MX8MP_IOMUXC_UART3_TXD__UART1_DCE_RTS, but without uart-has-rtscts on
the node, imx_uart_probe() leaves sport->have_rtscts false.  As a result,
imx_uart_set_termios() clears CRTSCTS and imx_uart_startup() ignores the
RTS pin, leaving hardware flow control and RS485 unusable on uart1.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1794334398.git.stefano.r@variscite.com?part=3