From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH v2 0/7] rtc: sun6i: Fix the RTC accuracy Date: Tue, 24 Jan 2017 18:49:35 +0100 Message-ID: <20170124174935.att4s7mqfbyxkxqk@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 Hi, On 23/01/2017 at 11:41:45 +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 > > Changes from v1: > - Force the muxing to the external oscillator even for old DT > - Make the patches a bit more stable friendly > - Change the bindings to have a cell of 1, to account for the external > output of the oscillator > - Split the driver remove() removal into a separate patch and switched to > devm > - Reordered the patches > > Maxime Ripard (7): > rtc: sun6i: Disable the build as a module > rtc: sun6i: Add some locking > rtc: sun6i: Switch to the external oscillator > rtc: sun6i: Expose the 32kHz oscillator > rtc: sun6i: Switch to devm_rtc_device_register > ARM: sun8i: a23/a33: Enable the real LOSC and use it > ARM: sun8i: a23/a33: Add the oscillators accuracy > I've applied 1/7 to 5/7. Thanks! -- 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.