[#3994] echo 'enabled' to /sys/class/rtc/rtc0/power/wakeup don't work

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[#3994] echo 'enabled' to /sys/class/rtc/rtc0/power/wakeup don't work

Submitted By: Vivi Li

Open Date

2008-03-28 07:27:23     Close Date

2008-03-28 20:49:56

Priority:

Medium     Assignee:

Mike Frysinger

Status:

Closed     Fixed In Release:

N/A

Found In Release:

N/A     Release:

Category:

N/A     Board:

N/A

Processor:

N/A     Silicon Revision:

Is this bug repeatable?:

Yes     Resolution:

Rejected

Uboot version or rev.:

    Toolchain version or rev.:

08r1-rc8

App binary format:

N/A     

Summary: echo 'enabled' to /sys/class/rtc/rtc0/power/wakeup don't work

Details:

 

For power management, I can wake up system by rtc without echoing 'enabled' to /sys/class/rtc/rtc0/power/wakeup.

 

System should not be able to wake up by rtc unless echo 'enabled' to /sys/class/rtc/rtc0/power/wakeup.

 

Follow-ups

 

--- Mike Frysinger                                           2008-03-28 20:49:56

i think this is as designed.  wakeup sources are enabled by default.  you have

to echo "disabled" in order to turn them off.

 

linux-2.6.x/Documentation/power/devices.txt:

/sys/devices/.../power/wakeup files

-----------------------------------

All devices in the driver model have two flags to control handling of

wakeup events, which are hardware signals that can force the device and/or

system out of a low power state.  These are initialized by bus or device

driver code using device_init_wakeup(dev,can_wakeup).

 

The "can_wakeup" flag just records whether the device (and its

driver) can

physically support wakeup events.  When that flag is clear, the sysfs

"wakeup" file is empty, and device_may_wakeup() returns false.

 

For devices that can issue wakeup events, a separate flag controls whether

that device should try to use its wakeup mechanism.  The initial value of

device_may_wakeup() will be true, so that the device's "wakeup" file

holds

the value "enabled".  Userspace can change that to

"disabled" so that

device_may_wakeup() returns false; or change it back to "enabled" (so

that

it returns true again).

 

 

 

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