From mboxrd@z Thu Jan 1 00:00:00 1970 From: alexandre.belloni@free-electrons.com (Alexandre Belloni) Date: Fri, 16 Jan 2015 12:45:21 +0100 Subject: [RFC 2/2] clocksource: don't suspend/resume when unused In-Reply-To: <20150116110742.GJ3843@piout.net> References: <1421399874-29119-1-git-send-email-alexandre.belloni@free-electrons.com> <1421399874-29119-3-git-send-email-alexandre.belloni@free-electrons.com> <20150116103530.GB3843@piout.net> <54B8EA54.5020002@linaro.org> <20150116104804.GE3843@piout.net> <54B8EF15.4000602@linaro.org> <20150116110742.GJ3843@piout.net> Message-ID: <20150116114521.GQ3843@piout.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 16/01/2015 at 12:07:42 +0100, Alexandre Belloni wrote : > On 16/01/2015 at 11:59:33 +0100, Daniel Lezcano wrote : > > On 01/16/2015 11:48 AM, Alexandre Belloni wrote: > > >Hi, > > > > > >On 16/01/2015 at 11:39:16 +0100, Daniel Lezcano wrote : > > >>>Isn't that already the case? > > >>>Right now, if you call clocksource_suspend, it doesn't matter whether > > >>>the clocksource has an enable or not, it will be suspended. Maybe I'm > > >>>mistaken but my patch doesn't seem to change that behaviour. > > >> > > >>Actually, if there is no enable/disable callback, then CLOCK_SOURCE_USED > > >>will be never set, hence the condition will always fail and the suspend > > >>callback won't be called. > > >> > > > > > >It is set in clocksource_enable/disable, even if there is no > > >enable/disable callback. > > > > Ah, right. But shouldn't we set the flag only if the callback is present and > > succeed as Boris mentioned it ? > > > > What Boris was suggesting was that if the enable exist, set it only if > it succeed. Which gives something like that: > > int clocksource_enable(struct clocksource *cs) > { > int ret = 0; > > if (cs->enable) > ret = cs->enable(cs); > > if (!ret) > cs->flags |= CLOCK_SOURCE_USED; > > return 0; Obviously, that is return ret; > } > > I will use that version in v2. > > > -- > Alexandre Belloni, Free Electrons > Embedded Linux, Kernel and Android engineering > http://free-electrons.com -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com