Re: [PATCH] arm64: dts: rockchip: Change serial baud rate for Pinephone Pro to 1.5 MB

From: Javier Martinez Canillas
Date: Tue Apr 04 2023 - 07:43:35 EST


Martijn Braam <martijn@xxxxxxxxx> writes:

> On 4/4/23 09:51, Heiko Stübner wrote:
>> Hi,
>>
>> Am Montag, 3. April 2023, 19:59:37 CEST schrieb Javier Martinez Canillas:
>>> This baud rate is set for the device by mainline u-boot and is also what
>>> is set in the Pinebook Pro Device Tree, which is a device similar to the
>>> PinePhone Pro but with a different form factor.
>>>
>>> Otherwise, the baud rate of the firmware and Linux don't match by default
>>> and a 'console=ttyS2,1500000n8' kernel command line parameter is required
>>> to have proper output for both.
>> The interesting question is always if this will break someone else's setup.
>> I've never really understood the strange setting of 1.5MBps, but on the
>> other hand it _is_ a reality on most boards.
>
> It breaks my device test setup at least. The extra speed isn't worth the
> hassle

More than the extra speed is to have consistency accross all the rockchip
devices in upstream and also sync with mainline u-boot.

> of having a few devices at weird baudrates and the bootloader already
> starts outputting debug logs at 115200 baud.
>

And mine starts outputting at 1.5MBps :) I guess that there isn't a one
size fits all, so the question is whether the bikeshed color is what was
painted in all other rockchip boards or the one that Tow-Boot has chosen.

--
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat