On Fri, 31 Aug 2012, Aaron Lu wrote:

quoted

In patch 5/7, your implementation of may_power_off is written in such a
way that if the drive is already powered off when userspace clears the
flag, the drive is not automatically powered back on.  Maybe this is
what you want?

No, actually I didn't consider this.

What about I do this when may_power_off is set to 0:
In its store function, if the device is runtime suspended(which means it
is in powered off state since may_power_off was 1 before this store call)
I'll set the flag to 0 and then runtime resume this device.

You might also want to runtime resume the device if may_power_off is
changed from 0 to 1.  Then it will power down when it suspends again
instead of just remaining powered up.

Alan Stern