On Thu, Oct 25, 2012 at 09:23:18PM +0100, Jon Hunter wrote: > Commit 7be2958 (ARM: PMU: Add runtime PM Support) updated the ARM PMU code to > use runtime PM which was prototyped and validated on the OMAP devices. In this > commit, there is no call pm_runtime_enable() and for OMAP devices > pm_runtime_enable() is currently being called from the OMAP PMU code when the > PMU device is created. However, there are two problems with this: > > 1. For any other ARM device wishing to use runtime PM for PMU they will need > to call pm_runtime_enable() for runtime PM to work. > 2. When booting with device-tree and using device-tree to create the PMU > device, pm_runtime_enable() needs to be called from within the ARM PERF > driver as we are no longer calling any device specific code to create the > device. Hence, PMU does not work on OMAP devices that use the runtime PM > callbacks when using device-tree to create the PMU device. > > Therefore, call pm_runtime_enable() directly from the ARM PMU driver when > registering the device. For platforms that do not use runtime PM, > pm_runtime_enable() does nothing and for platforms that do use runtime PM but > may not require it specifically for PMU, this will just add a little overhead > when initialising and uninitialising the PMU device. > > Tested with PERF on OMAP2420, OMAP3430 and OMAP4460. > > V2 changes: > - Call pm_runtime_enable() unconditionally on registering the PMU device. > > Signed-off-by: Jon Hunter <jon-hunter@xxxxxx> > --- Cheers Jon! Looks a bit weird without the matching pm_runtime_disable, but we don't really have anywhere to put that since the PMU is not deregistered. Can we split this patch into two (even smaller!) patches so that I can take the perf part and the omap bit can go to Tony? Will -- 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
