From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH 0/6] rtc: sun6i: Fix the RTC accuracy Date: Sun, 22 Jan 2017 15:32:44 +0100 Message-ID: <20170122143244.n2d4fpxnt62tkwtt@piout.net> References: Reply-To: rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Sender: rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Content-Disposition: inline In-Reply-To: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: Maxime Ripard Cc: Alessandro Zummo , Chen-Yu Tsai , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Rob Herring , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 20/01/2017 at 16:56:37 +0100, Maxime Ripard wrote : > Hi, > > The RTC used in the A31 and later SoC has an accuracy issue, which is > already significant even after a couple of hours. > > This is due to the fact that the oscillator used by default is an internal > and very inaccurate one. > > A first attempt at fixing that by switching to the external oscillator was > done in the patch "rtc: sun6i: Switch to the external oscillator". However, > it turned out to be problematic since it was tracked properly in the clock > framework, which might lead to some clocks being disabled, even though > their devices were not notified. > > This is a second attempt, this time by making it part of the CCF. It > turned out to be a bit more complicated than one would expect since the mux > found inside the RTC also controls one of the input of the main clock unit. > Therefore, it needs to be probed before the main clock unit driver. > > Let me know what you think, > Maxime > > Maxime Ripard (6): > rtc: sun6i: Expose the 32kHz oscillator > rtc: sun6i: Add some locking > rtc: sun6i: Disable the build as a module > rtc: sun6i: Force the mux to the external oscillator > ARM: sun8i: a23/a33: Enable the real LOSC and use it > ARM: sun8i: a23/a33: Add the oscillators accuracy > As Chen-Yu mentioned, maybe you can reorder some patches so they can go in stable. > Documentation/devicetree/bindings/rtc/sun6i-rtc.txt | 8 +- > arch/arm/boot/dts/sun8i-a23-a33.dtsi | 15 +- > drivers/rtc/Kconfig | 2 +- > drivers/rtc/rtc-sun6i.c | 189 +++++++++++-- > 4 files changed, 181 insertions(+), 33 deletions(-) > > base-commit: 99cef370ac9939df2aeb16c96d07e842b2fa8201 > -- > git-series 0.8.11 -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/d/optout.