/sys/power/state contents

Why does it say:

 *      show() returns what states are supported, which is hard-coded to
 *      'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
 *      'disk' (Suspend-to-Disk).

and not use the ->valid call to limit what is displayed to what can be entered?

Quoted 2 lines

and not use the ->valid call to limit what is displayed to what can be entered?

You mean, exactly like the valid_state() function already does??

You mean, exactly like the valid_state() function already does??

Quoted 1 line · David Brownell

You mean, exactly like the valid_state() function already does??

Which actually opens up another question. Why is the default 1 instead of 0? If an arch doesn't have any callbacks, why announce that it can do it? It would seem more sensible to me to force an arch that wants to support this to also have a valid call in order to announce it. Not that it actually will work, but why even show it?