From mboxrd@z Thu Jan 1 00:00:00 1970 From: alexandre.belloni@free-electrons.com (Alexandre Belloni) Date: Tue, 24 Jan 2017 18:49:35 +0100 Subject: [PATCH v2 0/7] rtc: sun6i: Fix the RTC accuracy In-Reply-To: References: Message-ID: <20170124174935.att4s7mqfbyxkxqk@piout.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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