From: Heiko Stuebner <heiko@sntech.de>
To: Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Diederik de Haas <diederik@cknow-tech.com>
Cc: Ricardo Pardini <ricardo@pardini.net>,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
Diederik de Haas <diederik@cknow-tech.com>
Subject: Re: [PATCH] arm64: dts: rockchip: Fix i2c6 clock-frequency on NanoPC-T6
Date: Sat, 12 Sep 2026 14:41:32 +0200 [thread overview]
Message-ID: <2071782.usQuhbGJ8B@phil> (raw)
In-Reply-To: <20260911152911.2088363-1-diederik@cknow-tech.com>
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
next prev parent reply other threads:[~2026-09-12 12:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-11 15:28 Diederik de Haas
2026-09-12 12:41 ` Heiko Stuebner [this message]
2026-09-12 14:16 ` Diederik de Haas
2026-09-12 15:48 ` Diederik de Haas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2071782.usQuhbGJ8B@phil \
--to=heiko@sntech.de \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=diederik@cknow-tech.com \
--cc=krzk+dt@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=ricardo@pardini.net \
--cc=robh@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®