From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Mon, 8 Feb 2016 15:06:14 +0100 Subject: [PATCH v1] clocksource: atmel-pit: register as a sched_clock In-Reply-To: <56B89910.3060305@linaro.org> References: <1454606493-15094-1-git-send-email-romain.izard.pro@gmail.com> <56B89910.3060305@linaro.org> Message-ID: <20160208150614.5e87133e@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org + Alexandre Hi Daniel, On Mon, 8 Feb 2016 14:33:04 +0100 Daniel Lezcano wrote: > On 02/04/2016 06:21 PM, Romain Izard wrote: > > Register the counter of the Periodic Interval Timer as a possible source > > for sched_clock. This provides a better precision than the jiffies-based > > default. > > > > Signed-off-by: Romain Izard > > Nicolas, Boris, > > Are you ok with this patch ? Not sure yet :). On most platforms we are also declaring a clocksource based on the TCB IP, and this one provides a better precision than the PIT clocksource. What happens if the PIT is de-activated while it's still supposed to provide the sched_clock(). Is there a way to flag the clocksource as still needed so that the core does not shut it down by when the TCB clocksource comes in. Best Regards, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com