Hi Mark, On Mon, Jun 17, 2013 at 11:53 PM, Mark Rutland <[email protected]> wrote: > On Mon, Jun 17, 2013 at 01:20:56AM +0100, Magnus Damm wrote: >> From: Magnus Damm <[email protected]> >> >> Modify the ARM architected timer driver to not set C3STOP >> in case CPU_IDLE is disabled. This is a short term fix that >> allows use of high resolution timers even though no additional >> clock event is registered. >> >> Not-really-Signed-off-by: Magnus Damm <[email protected]> >> --- >> >> If someone cares about this case then perhaps it should be >> moved up to the clock event main code. The same issue should >> in theory trigger on all architectures, perhaps x86 people >> hunting for low latency may try to disable CPU_IDLE? > > I think that changing tick_is_oneshot_capable and friends to only worry about > C3STOP when CPU_IDLE is enabled would be a nicer solution. That way you enable > all clock_event_devices with C3STOP to function as high resolution timers when > CPU_IDLE's selected. Presenting the hardware differently depending on CPU_IDLE > feels wrong.
I agree that doing this in the clock event driver is a bit odd. So because of that I just posted this patch: [PATCH/RFC] clockevents: Ignore C3STOP when CPUIdle is disabled > Having some other clock_event_device would be a nicer solution still. No doubt that another clock event device helps, but mainly together with CPU Idle IMO. Thanks for your comments! / magnus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
