On Wednesday, 9 of January 2008, David Brownell wrote: > The /sys/devices/.../power/state files have been gone for a while > now, but I just noticed some documentation that still refers to > them. (Fortunately described as DEPRECATED and WILL REMOVE). > > Time to remove that obsolete documentation too ... > > Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx> Acked-by: Rafael J. Wysocki <rjw@xxxxxxx> > --- > Documentation/power/devices.txt | 49 ---------------------------------------- > 1 file changed, 49 deletions(-) > > --- g26.orig/Documentation/power/devices.txt 2008-01-09 12:05:51.000000000 -0800 > +++ g26/Documentation/power/devices.txt 2008-01-09 12:06:33.000000000 -0800 > @@ -502,52 +502,3 @@ If the CPU can have a "cpufreq" driver, > to shift to lower voltage settings and reduce the power cost of executing > a given number of instructions. (Without voltage adjustment, it's rare > for cpufreq to save much power; the cost-per-instruction must go down.) > - > - > -/sys/devices/.../power/state files > -================================== > -For now you can also test some of this functionality using sysfs. > - > - DEPRECATED: USE "power/state" ONLY FOR DRIVER TESTING, AND > - AVOID USING dev->power.power_state IN DRIVERS. > - > - THESE WILL BE REMOVED. IF THE "power/state" FILE GETS REPLACED, > - IT WILL BECOME SOMETHING COUPLED TO THE BUS OR DRIVER. > - > -In each device's directory, there is a 'power' directory, which contains > -at least a 'state' file. The value of this field is effectively boolean, > -PM_EVENT_ON or PM_EVENT_SUSPEND. > - > - * Reading from this file displays a value corresponding to > - the power.power_state.event field. All nonzero values are > - displayed as "2", corresponding to a low power state; zero > - is displayed as "0", corresponding to normal operation. > - > - * Writing to this file initiates a transition using the > - specified event code number; only '0', '2', and '3' are > - accepted (without a newline); '2' and '3' are both > - mapped to PM_EVENT_SUSPEND. > - > -On writes, the PM core relies on that recorded event code and the device/bus > -capabilities to determine whether it uses a partial suspend() or resume() > -sequence to change things so that the recorded event corresponds to the > -numeric parameter. > - > - - If the bus requires the irqs-disabled suspend_late()/resume_early() > - phases, writes fail because those operations are not supported here. > - > - - If the recorded value is the expected value, nothing is done. > - > - - If the recorded value is nonzero, the device is partially resumed, > - using the bus.resume() and/or class.resume() methods. > - > - - If the target value is nonzero, the device is partially suspended, > - using the class.suspend() and/or bus.suspend() methods and the > - PM_EVENT_SUSPEND message. > - > -Drivers have no way to tell whether their suspend() and resume() calls > -have come through the sysfs power/state file or as part of entering a > -system sleep state, except that when accessed through sysfs the normal > -parent/child sequencing rules are ignored. Drivers (such as bus, bridge, > -or hub drivers) which expose child devices may need to enforce those rules > -on their own. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > > -- "Premature optimization is the root of all evil." - Donald Knuth _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
