Public bug reported:
Kernel 4.2 includes a significant commit
(87549141d516aee71d511138e27117c41e8aef68), after the patch the files
and directory are present even if the CPU is offline. If the CPU is
offline, writing to those files isn't allowed and so the echo in
94cpufreq fails.
If the failed echo is not the last pass through the loop, then
the bad exit code gets overwritten with a good one before
the loop exits. If the failed echo is the last pass through the loop, due to
the highest numbered CPU being offline, then then 94cpufreq returns an error
code and pm-suspend aborts.
So what is needed is something like (and this doesn't actually work
yet):
hibernate_cpufreq()
{
( cd /sys/devices/system/cpu/
for x in cpu[0-9]*; do
# if cpufreq is a symlink, it is handled by another cpu. Skip.
[ -L "$x/cpufreq" ] && continue
gov="$x/cpufreq/scaling_governor"
# if we do not have a scaling_governor file, skip.
[ -f "$gov" ] || continue
+ # if the CPU is offline, skip, unless no file, i.e. CPU0.
+ [ $(cat "$x/online") = "1" -o ! -f "$x/online" ] || continue
Or
+ if [ $(cat "$x/online") = "1" ] || [ ! -f "$x/online" ]; then
+ continue;
+ fi
Or something similar that actually works.
# if our temporary governor is not available, skip.
grep -q "$TEMPORARY_CPUFREQ_GOVERNOR" \
"$x/cpufreq/scaling_available_governors" || continue
savestate "${x}_governor" < "$gov"
echo "$TEMPORARY_CPUFREQ_GOVERNOR" > "$gov"
done )
}
Or just force a good return code at the end (which is what I'm doing
now, so that I can move on).
Note: I also filed this same bug report upstream.
https://bugs.freedesktop.org/show_bug.cgi?id=91914
** Affects: pm-utils (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pm-utils in Ubuntu.
https://bugs.launchpad.net/bugs/1493156
Title:
pm-suspend aborts if highest numbered CPU offline, as of kernel 4.2
Status in pm-utils package in Ubuntu:
New
Bug description:
Kernel 4.2 includes a significant commit
(87549141d516aee71d511138e27117c41e8aef68), after the patch the files
and directory are present even if the CPU is offline. If the CPU is
offline, writing to those files isn't allowed and so the echo in
94cpufreq fails.
If the failed echo is not the last pass through the loop, then
the bad exit code gets overwritten with a good one before
the loop exits. If the failed echo is the last pass through the loop, due to
the highest numbered CPU being offline, then then 94cpufreq returns an error
code and pm-suspend aborts.
So what is needed is something like (and this doesn't actually work
yet):
hibernate_cpufreq()
{
( cd /sys/devices/system/cpu/
for x in cpu[0-9]*; do
# if cpufreq is a symlink, it is handled by another cpu. Skip.
[ -L "$x/cpufreq" ] && continue
gov="$x/cpufreq/scaling_governor"
# if we do not have a scaling_governor file, skip.
[ -f "$gov" ] || continue
+ # if the CPU is offline, skip, unless no file, i.e. CPU0.
+ [ $(cat "$x/online") = "1" -o ! -f "$x/online" ] || continue
Or
+ if [ $(cat "$x/online") = "1" ] || [ ! -f "$x/online" ]; then
+ continue;
+ fi
Or something similar that actually works.
# if our temporary governor is not available, skip.
grep -q "$TEMPORARY_CPUFREQ_GOVERNOR" \
"$x/cpufreq/scaling_available_governors" || continue
savestate "${x}_governor" < "$gov"
echo "$TEMPORARY_CPUFREQ_GOVERNOR" > "$gov"
done )
}
Or just force a good return code at the end (which is what I'm doing
now, so that I can move on).
Note: I also filed this same bug report upstream.
https://bugs.freedesktop.org/show_bug.cgi?id=91914
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/1493156/+subscriptions
--
Mailing list: https://launchpad.net/~touch-packages
Post to : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help : https://help.launchpad.net/ListHelp
