Hi Mark, On 04/11/2012 02:05 PM, Mark A. Greer wrote: > From: "Mark A. Greer" <mgreer@xxxxxxxxxxxxxxx> > > Currently in the OMAP3 code, cpu_idle() calls pm_idle(), > which is a function pointer set to omap3_pm_idle()). > omap3_pm_idle() calls omap_sram_idle() which eventually > causes a 'wfi' instruction to be executed effectively > putting the system to sleep. It is assumed that an > I/O wake-up event will occur to wake the system up again. > This doesn't work on systems that don't support I/O wake-ups > (indicated by omap3_has_io_wakeup() returning false). > > Leaving pm_idle() pointing to default_idle() won't work > either because the cpu_<processor>_do_idle() routine which > is eventually called may also execute a 'wfi' instruction > (e.g., cpu_v7_do_idle()). So with this change you will never execute wfi? I would have thought a timer or peripheral interrupt would be able to bring you out of wfi. IO wake-ups would only be needed for very low power states. At least that is how it is on OMAP devices. I am not sure how the AMxxx devices differ. 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
