Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [linux-pm][PATCH] base: Change power/wakeup output from "" to "unsupported" if wakeup feature isn't supported by a device | Date | Mon, 7 Jan 2008 02:57:58 +0100 |
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On Monday, 7 of January 2008, Yi Yang wrote: > On Fri, 2008-01-04 at 08:09 -0800, David Brownell wrote: > > > > This patch changes empty output to "unsupported" in order that a user knows > > > > wakeup feature isn't supported by this device when he/she > > > > 'cat /sys/devices/.../power/wakeup', please consider to apply, > > > > thanks. > > > > > > What about simply removing "wakuep" file if wakeup is not supported? > > > > It may not *stay* unsupported, so I think changing it in either > > of those permanent ways would be confusing/misleading. > > > > For example, USB devices have multiple states ... minimally, an > > unconfigured state, and a configured state. Some have multiple > > configurations. Only configured states can be wakeup-capable. > > So a given device might have three states, but support wakeup > > except in one of them... > If so, we can change "unsupported" to "unconfigurable" or "inoperable" > which can cover the states "unconfigured", "unsupported" and other > unknown states. :-).
The main problem with your patch is that is changes a documented behavior visible by the user space. That should be done very cautiously.
Thanks, Rafael
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