On Wed, Jul 4, 2012 at 3:56 PM, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > > On Wed, Jul 04, 2012 at 03:24:33PM +0530, Santosh Shilimkar wrote: > > ARM arch timers stop in low power state and hence can not wakeup CPUs in > > deeper idle states when used as cloc event devices. Marking these clock > > event > > devices with C3_STOP so that during lowpower states, the tick is managed > > by > > wakeup capable broadcast timer. > > Will tells me that the arch timers don't stop in low power modes, they > just can't produce wakeup events. Apparantly the spec says: > > The system counter must be implemented in an always-on power domain. > Use of lower-frequency modes must not affect the implemented accuracy. > > Are you sure your above description of the problem is correct? Yes. Will is right. The arch timers don't stop with a real time counter implementation. The issue is they are not wakeup capable hence you need a broad-cast switching which in turn needs C3_STOP. Regards Santosh -- 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
