Re: [PATCH 3/3] MIPS: dts: loongson64g-package: Switch to Loongson UART driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On Sun, Mar 15, 2026 at 07:41:43AM +0800, Rong Zhang wrote:
> Loongson64g is Loongson 3A4000, whose UART controller is compatible with
> Loongson 2K1500, which is NS16550A-compatible with an additional
> fractional frequency divisor register.
> 
> Update the compatible strings to reflect this, so that 3A4000 can
> benefit from the fractional frequency divisor provided by loongson-uart.
> This is required on some devices, otherwise their UART can't work at
> some high baud rates, e.g., 115200.
> 
> Tested on Loongson-LS3A4000-7A1000-NUC-SE with a 25MHz UART clock.
> Without fractional frequency divisor, the actual baud rate was 111607
> (25MHz / 16 / 14, measured value: 111545) and some USB-to-UART
> converters couldn't work with it at all. With fractional frequency
> divisor, the measured baud rate becomes 115207, which is quite accurate.
> 
> Signed-off-by: Rong Zhang <rongrong@oss.cipunited.com>
> ---
>  arch/mips/boot/dts/loongson/loongson64g-package.dtsi | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

DTS should be sent separately, don't mix independent patches targetting
serial tree.

Best regards,
Krzysztof