On Sat, 26 Sep 2015, Rafael J. Wysocki wrote: > > > So something like: > > > > > > echo on >/sys/.../power/control (in case the device was > > > already in runtime suspend with wakeups enabled) > > > echo off >/sys/.../power/wakeup > > > echo auto >/sys/.../power/control
Cases where the driver wants to avoid runtime suspend (while the device is active) because of bad wakeup support in the hardware can be handled easily enough. The runtime-idle or runtime-suspend callback routine can check whether wakeup == off; if it isn't then the callback should return -EBUSY. Thus the driver can prevent runtime suspend without any need to increment the usage counter. > > That, or there may be an additional value, say "aggressive", to write to the > > control file in which case it becomes just > > > > echo aggressive >/sys/.../power/control > > That said I suppose that the "off" value for the "wakeup" file might also be > useful in some other cases, so it likely is a better approach. We still need some sort of "inhibit" callback for cases where the driver doesn't want to go into runtime suspend but does want to turn off all I/O. Should this callback be triggered when the user writes "off" to power/wakeup, or when the user writes "inhibit" to power/control, or should there be a separate sysfs attribute? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
