On Mon, 2012-01-09 at 09:55 +0800, Yan, Zheng wrote: > On 01/09/2012 08:34 AM, Guy, Wey-Yi wrote: > > On Mon, 2012-01-09 at 09:01 +0800, Yan, Zheng wrote: > >> On 01/06/2012 05:47 PM, Johannes Berg wrote: > >>> [add linux-wireless] > >>> > >>> On Fri, 2012-01-06 at 10:41 +0800, Yan, Zheng wrote: > >>>> This simple patch adds open/close based runtime PM support to the iwlwifi driver. > >>>> Namely, make the driver suspend the device after shutting down the interface and > >>>> resume the device when activating the interface. In my test, suspending the device > >>>> can save about 0.4 watt power. The shortcoming is that the device no longer generate > >>>> rfkill changes interrupt. > >>> > >>> NACK due to that last sentence. There's no way we can live with that in > >>> the general case -- and your patch isn't even configurable afaict. And > >>> I'm sure polling the rfkill flag would use just as much energy. > >>> > >> It's configurable, runtime PM is disabled by default. > > > > Somehow I miss it, how you configure it? > > > change the value of /sys/devices/.../power/control to auto to enable the runtime PM. > (e.g echo auto > /sys/devices/pci0000:00/0000:00:1c.3/0000:02:00.0/power/control) I am not sure it is acceptable, how you expect user figure out the pci space especially the NIC can be in any of the PCI slots. > > >> > >>> There might be some value in this in a system that doesn't have a hard > >>> rfkill line, but that means this needs to be configurable since the > >>> device can't know whether there's a button or not [1]. > >>> > >> The patch targets system that only use software rfkill > > > > How you control that? > I can't. Our team is working on runtime PM project, the purpose of the patch is > more or less to demonstrate how much power can be saved. > I understand, but unless we figure out either make rkill interrupt works in runtime PM, or figure out the platform does not has HW RFKILL automatically, I don't see how this patch can upstream without generate a lot of issues and bug reports. Thanks Wey > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
