[Pm-utils] Some thoughts about some of the hooks

[Stefan Seyfried]

On Fri, Oct 06, 2006 at 10:01:19AM +0200, Tim Dijkstra wrote:
> On Fri, 6 Oct 2006 07:56:11 +0200
> Stefan Seyfried <seife at suse.de> wrote:
> 
> > Ok. I am going to try to move all our powersaved scripts to pm-utils,
> > and making it work with uswsusp (which is our default now) would have
> > been one of the tasks anyway :-)
> 
> Very good. Takes something from my todo list;)

how about this:

Index: functions
===================================================================
RCS file: /cvs/pm-utils/pm-utils/pm/functions,v
retrieving revision 1.20
diff -u -p -r1.20 functions
--- functions	28 Sep 2006 21:25:36 -0000	1.20
+++ functions	6 Oct 2006 09:27:49 -0000
@@ -96,14 +102,32 @@ pm_main()
 	run_hooks "$1"
 	sync ; sync ; sync
 
+	[ -e /etc/pm/config.d/$1 ] && . /etc/pm/config.d/$1
+
 	case "$1" in
 		suspend)
 			pm-pmu --suspend || echo -n "mem" > /sys/power/state
 			run_hooks resume reverse
 			;;
 		hibernate)
-			echo -n "platform" > /sys/power/disk
-			echo -n "disk" > /sys/power/state
+			if [ -z "$HIBERNATE" ]; then
+				if [ -x /usr/sbin/s2disk -a -c /dev/snapshot ]; then
+					HIBERNATE="userspace"
+				else
+					HIBERNATE="kernel"
+				fi
+			fi
+			if checkhibernate; then
+				case $HIBERNATE in
+					userspace)
+						/usr/sbin/s2disk -f /var/lib/s2disk.conf
+						;;
+					kernel)
+						echo -n "platform" > /sys/power/disk
+						echo -n "disk" > /sys/power/state
+						;;
+				esac
+			fi
 			run_hooks thaw reverse
 			;;
 	esac
@@ -155,3 +213,52 @@ restorestate()
 {
 	eval echo \$${1}_STATE
 }
+
+# sanity check the environment if resume will be possible after hibernate
+checkhibernate()
+{
+	if [ "$HIBERNATE" = "kernel" ]; then
+		read RDEV < /sys/power/resume
+		if [ "$RDEV" = "0:0" ]; then
+			# DEBUG "no resume partition set"
+			# maybe "resume=..." was given, but initrd did not set up
+			# /sys/power/resume correctly.
+			return 1
+		fi
+		if [ -n "$IMAGE_SIZE" -a -w /sys/power/image_size ]; then
+			echo "$IMAGE_SIZE" > /sys/power/image_size 2>/dev/null
+		fi
+	fi
+	RDEV=""
+	read CMDLINE < /proc/cmdline
+	for CMD in $CMDLINE; do
+		case $CMD in
+			resume=*) RDEV=${CMD#*=}
+			break ;;
+		esac
+	done
+	if [ -z "$RDEV" ]; then
+		# DEBUG "no resume parameter"
+		return 1
+	fi
+	while read SDEV STYPE DUMMY; do
+		[ "$STYPE" != "partition" ] && continue
+		[ "$SDEV" = "$RDEV" ] && break
+		SDEV=""
+	done < /proc/swaps
+	if [ -z "$SDEV" ]; then
+		# DEBUG "resume partition '$RDEV' not swapon'ed"
+		return 1
+	fi
+	if [ "$HIBERNATE" = "userspace" ]; then
+		rm -f /var/lib/s2disk.conf
+		echo "resume device = $RDEV" >> /var/lib/s2disk.conf
+		if [ -n "$IMAGE_SIZE" ]; then
+			echo "image size = $IMAGE_SIZE" >> /var/lib/s2disk.conf
+		# add the parameters from /etc/suspend.conf to /var/lib/s2disk.conf
+		if [ -e /etc/suspend.conf ]; then
+			sed '/^[[:space:]]*\(#\|$\)/d;' /etc/suspend.conf >> /var/lib/s2disk.conf
+		fi
+	fi
+	return 0
+}


This is basically how i did it until now in powersaved.
Precondition:
- your initrd does invoke resume with the device from "resume=". I think it
  is a good idea to use the well known resume parameter also for userspace
  suspend. Generally, the user should not need to care about which method he
  uses.
  Right now i do not even copy /etc/suspend.conf into the initrd anymore
  since it is not needed for resume.

Then i generate a temporary suspend config file in /var/lib/s2disk.conf from
the resume= parameter (read from /proc/cmdline) and from IMAGE_SIZE (which
might be set in /etc/pm/config.d/hibernate or calculated intelligently from
the free swap space and the total amount of system memory, this is not yet
in this patch).
I append any options from /etc/suspend.conf to this temporary config file.
Since s2disk just takes the latest incarnation of an option, the settings
from /etc/suspend.conf override our automatic determined setting.
I ship an empty (all options commented out) config file, and it just works
out of the box, if the resume= parameter is correctly set (done by the
installer).

What do you think about that?

-- 
Stefan Seyfried
QA / R&D Team Mobile Devices        |              "Any ideas, John?"
SUSE LINUX Products GmbH, Nürnberg  | "Well, surrounding them's out."