On 01/30/2013 11:48 AM, Jon Hunter wrote: > > On 01/24/2013 04:30 PM, Jon Hunter wrote: >> Hi Vaibhav, >> >> On 12/31/2012 07:07 AM, Vaibhav Bedia wrote: >>> AM33XX has two timers (DTIMER0/1) in the WKUP domain. >>> On GP devices the source of DMTIMER0 is fixed to an >>> inaccurate internal 32k RC oscillator and this makes >>> the DMTIMER0 practically either as a clocksource or >>> as clockevent. >>> >>> Currently the timer instance in WKUP domain is used >>> as the clockevent and the timer in non-WKUP domain >>> as the clocksource. DMTIMER1 in WKUP domain can keep >>> running in suspend from a 32K clock fed from external >>> OSC and can serve as the persistent clock for the kernel. >>> To enable this, interchange the timers used as clocksource >>> and clockevent for AM33XX. >> >> I have been thinking about this some more. In the case where we are >> using gptimers for both clock-events and clock-source (on both AM33xx >> and OMAP) and I am wondering if it makes sense to switch the timers so >> that we use the always-on timer for clock-source and a different one >> from clock-events. >> >> For OMAP, if we are not using the 32k-sync for clock-source, then we are >> never going to achieve low power states during idle as we will always >> have one gptimer running. And in this case, to your point below, it >> would be better to use the always-on for clock-source so that in suspend >> we can at least hit low power states and maintain time. > > I have posted a patch today [1] that I hope will address this issue for > you. Can you give that a try? By the way, this need to be applied on top of the fix I sent yesterday to pass the property. Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
