Documentation: Ask driver writers to provide PM support

Add a paragraph in Documentation/SubmittingDrivers requesting that the
basic PM support be provided by new device drivers.

Add two new documents in Documentation/power/ giving general instructions
on debugging the suspend/resume functionality and testing the suspend and
resume support in device drivers.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: David Brownell <david-b@pacbell.net>
Cc: Nigel Cunningham <ncunningham@linuxmail.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/SubmittingDrivers b/Documentation/SubmittingDrivers
index 58bead0..d7e2642 100644
--- a/Documentation/SubmittingDrivers
+++ b/Documentation/SubmittingDrivers
@@ -87,6 +87,21 @@
 		driver that intentionally obfuscates how the hardware works
 		it will go in the bitbucket.
 
+PM support:	Since Linux is used on many portable and desktop systems, your
+		driver is likely to be used on such a system and therefore it
+		should support basic power management by implementing, if
+		necessary, the .suspend and .resume methods used during the
+		system-wide suspend and resume transitions.  You should verify
+		that your driver correctly handles the suspend and resume, but
+		if you are unable to ensure that, please at least define the
+		.suspend method returning the -ENOSYS ("Function not
+		implemented") error.  You should also try to make sure that your
+		driver uses as little power as possible when it's not doing
+		anything.  For the driver testing instructions see
+		Documentation/power/drivers-testing.txt and for a relatively
+		complete overview of the power management issues related to
+		drivers see Documentation/power/devices.txt .
+
 Control:	In general if there is active maintainance of a driver by
 		the author then patches will be redirected to them unless
 		they are totally obvious and without need of checking.