From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5344E21D00A; Sat, 12 Sep 2026 12:41:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789216901; cv=none; b=MEqsKmsJh/OkSmjm56Bf+HVpr2qdZDrizTmPwFXHjJFdxc+IHJzqTpyjmcO2gnzCVzMK9tAdwdQs0QWE0elJCEBhRktskBkgYFWPYNYqeECGLywn4INOk5UaRUlGw5/JaAK0YNHCIOX2Lk3uE/JycAruawt0lyh9hAu73I2ITTc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789216901; c=relaxed/simple; bh=g/pEqhnkpHm0z8rgEAHyFA5daCvErBvF4/BNaXixSoY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hnd+LQ/UU9ZpEGj7hVKKJNQW10cAiXmKOyJwhnD+mg4OWcg0wBStQp148tbdMVekbMxfifaPNInnsZHa3a9XzwexTQ6UtLw9O/5N4qmqGeaZuc6p4eEnWWagUD9IGRGkqPhM+9StaOHBDfiElcHFaCYkFjabLHipIIE/b74Yl2Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=YUi0DHbq; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="YUi0DHbq" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To; bh=vcYxdHFVaT3A3UhEJHDH4JKBcMrG+Bk4FHzp8MJW9wI=; b=YUi0DHbq1FTxQjpS3c8/wRf/Xv HZHktQqIgqe3hnLAURzxfaJnJY9kgm4aE4fWVmP23VbsnkdwErBetYiisLpdDTZVsCXR4ZqyIJL+5 5R9UE5xmokeGp9rX62xphcRPYBjgjjlJ+Hl+CBzQjJTh+N92yprp/PZ8XG1fv0sTo3PSwVKjOruUe wvzYtJ3b9w5HlL48Z5EKWY8jbwDJcl79+sPEW722V5Lz6tUyG9oU3XmDkL4XtZP2xJWcXPXHljn63 P0A4trSTeWklI64l+GCLIUbRuPeXhk0/wP1KLXRtYzPmNfPEovNbbzpQ1bQRair6imQp8KVqQQGWZ z3CsikYA==; From: Heiko Stuebner To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Diederik de Haas Cc: Ricardo Pardini , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Diederik de Haas Subject: Re: [PATCH] arm64: dts: rockchip: Fix i2c6 clock-frequency on NanoPC-T6 Date: Sat, 12 Sep 2026 14:41:32 +0200 Message-ID: <2071782.usQuhbGJ8B@phil> In-Reply-To: <20260911152911.2088363-1-diederik@cknow-tech.com> References: <20260911152911.2088363-1-diederik@cknow-tech.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Am Freitag, 11. September 2026, 17:28:33 Mitteleurop=C3=A4ische 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 >=20 > rtc-hym8563 6-0051: no valid clock/calendar values available > rtc-hym8563 6-0051: hctosys: unable to read the hardware clock >=20 > 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