From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keerthy Subject: Re: [PATCH v2 2/6] rtc: omap: Add external clock enabling support Date: Fri, 14 Aug 2015 10:25:11 +0530 Message-ID: <55CD74AF.4020803@ti.com> References: <1439198906-31189-1-git-send-email-j-keerthy@ti.com> <1439198906-31189-3-git-send-email-j-keerthy@ti.com> <55CB99C2.7010007@ti.com> <20150812201636.GJ3411@piout.net> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Paul Walmsley , Alexandre Belloni , Keerthy Cc: tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, johan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, grygorii.strashko-l0cyMroinI0@public.gmane.org, rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, bcousson-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, nm-l0cyMroinI0@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, t-kristo-l0cyMroinI0@public.gmane.org List-Id: devicetree@vger.kernel.org On Friday 14 August 2015 01:47 AM, Paul Walmsley wrote: > Hi guys > > On Wed, 12 Aug 2015, Alexandre Belloni wrote: > >> On 13/08/2015 at 00:38:50 +0530, Keerthy wrote : >>> The intent here is to switch to a higher precision clock which is the >>> internal clock when available. >>> >>> Alexandre, >>> >>> Is dynamic switching preferred over sticking to external clock always if >>> present? >> >> I'd say that I don't really care. I'd say the best would be to make a >> decision based on clock-accuracy but maybe that is an information you >> don't have yet. Anyway, this could be added at a later date. > > Either the clock mux logic is glitchless, in which case the RTC is likely > to lose at least 31 microseconds per switch; or it's not glitchless, in > which case it's unsafe to switch the RTC clock source while the clock > isn't gated. Keerthy, before submitting this patch for merging, I'd > suggest consulting your hardware folks to figure out which case it is. Paul, Thanks. Yes so i am doing the static way first. Keeping external clock always if available. Switching dynamically can be done later with more clarifications. Thanks, Keerthy > > > - Paul > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html