On Sat, Jul 8, 2017 at 3:03 AM, Derek Basehore <dbasehore@xxxxxxxxxxxx> wrote: > Adds a new feature to tick to schedule wakeups on a CPU during freeze. > This won't fully wake up the system (devices are not resumed), but > allow simple platform functionality to be run during freeze with > little power impact. > > This implementation allows an idle driver to setup a timer event with > the clock event device when entering freeze by calling > tick_set_freeze_event. Only one caller should exist for the function. > > tick_freeze_event_expired is used to check if the timer went off when > the CPU wakes. > > The event is cleared by tick_clear_freeze_event. > +int tick_set_freeze_event(int cpu, ktime_t delta) > +{ > + printk_deferred(KERN_WARNING > + "[%s] unsupported by clock event device\n", Can it be one line? > + printk_deferred(KERN_WARNING > + "[%s] clock event device in use\n", Ditto. > + printk_deferred(KERN_WARNING > + "[%s] %lluns outside range: [%lluns, %lluns]\n", Ditto. > + printk_deferred(KERN_WARNING > + "Failed to program freeze event\n"); Ditto. > +int tick_freeze_event_expired(int cpu) > +{ > + struct clock_event_device *dev = per_cpu(tick_cpu_device, cpu).evtdev; > + > + if (!(dev && dev->event_expired)) Usually we use a pattern (!x || !x->y). At least for me it looks slightly better to read. > + return 0; > + > + return dev->event_expired(dev); > +} -- With Best Regards, Andy Shevchenko