From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Tue, 15 May 2018 12:27:15 +0200 Subject: [RFC PATCH 00/10] Add persistent clock support In-Reply-To: References: Message-ID: <20180515102715.GO29062@mai> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, May 14, 2018 at 04:55:26PM +0800, Baolin Wang wrote: > Hi, > > We will meet below issues when compensating the suspend time for the timekeeping. > > 1. We have too many different ways of dealing with persistent timekeeping > across architectures, so it is hard for one driver to compatable with different > architectures. > > 2. On some platforms (such as Spreadtrum platform), we registered the high > resolution timer as one clocksource to update the OS time, but the high > resolution timer will be stopped in suspend state. So we use another one > always-on timer (but low resolution) to calculate the suspend time to > compensate the OS time. Though we can register the always-on timer as one > clocksource, we need re-calculate the mult/shift with one larger conversion > range to calculate the suspend time and need update the clock in case of > running over the always-on timer. First, can you elaborate what you mean by 'suspend state' ? On which power domain the clocksource belongs to? -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog