Re: [PATCH] arm64: dts: rockchip: Fix i2c6 clock-frequency on NanoPC-T6

[Heiko Stuebner]

Am Freitag, 11. September 2026, 17:28:33 Mitteleuropäische Sommerzeit schrieb Diederik de Haas:
> The i2c6 bus needs to run at 200kHz, because at the default frequency of
> 100kHz it may fail to find the RTC resulting in warnings/errors like
> 
>   rtc-hym8563 6-0051: no valid clock/calendar values available
>   rtc-hym8563 6-0051: hctosys: unable to read the hardware clock
> 
> But only sometimes. This should not happen when there is a battery backing
> the RTC, yet it does ... sometimes.

I'm confused, shouldn't a slower clock always work?
Like I understand how a clock that is too fast can cause issues due
to hardware limitations, but running the bus slower somehow shouldn't
cause issues?


Heiko