Power Management: Difference between revisions

(6 intermediate revisions by 2 users not shown)

Line 30:

systemd.services.your-service-name = {

description = "Service description here";

wantedBy = [ "post-resume.target" ];

after = [ "post-resume.target" ];

script = ''

echo "This should show up in the journal after resuming."

'';

serviceConfig.Type = "oneshot";

};

</syntaxhighlight>

Line 48:

Therefore, an example configuration could look like this:<syntaxhighlight lang="nix">

/*

// I'm hibernating into a logical volume that's also under LUKS. Pretty cool, right?

I'm hibernating into a logical volume that's also under LUKS. Pretty cool, right?

*/

swapDevices = [

Line 59:

Line 57:

boot.resumeDevice = "/dev/dm-7";

</syntaxhighlight>Derived from a system with the following output from <code>swapon -s</code> :<syntaxhighlight>

</syntaxhighlight>Derived from a system with the following output from <code>swapon -s</code> :<syntaxhighlight lang="text">Filename Type Size Used Priority

Filename Type Size Used Priority

/dev/dm-7 partition 67108860 00

/dev/zram0 partition 32881148 032767

/dev/zram0 partition 32881148 032767</syntaxhighlight>

</syntaxhighlight>

Test and use hibernation with the following command:<syntaxhighlight lang="nix">

Line 141:

Line 136:

After finding out which component is causing unwanted wakeups you can use the sysfs id to find out the "vendor" and "device" fields:

$ cat /sys/class/pci_bus/0000:04/device/0000:04:00.0/vendor

0x1987

Line 155:

Line 150:

'';

</syntaxhighlight>

=== Suspend blocked by <code>pre-sleep.service</code> ===

Sometimes, the system appears to suspend (Wi-Fi turns off, screen locks), but the hardware does not actually suspend, and all subsequent <code>systemctl suspend</code> or <code>systemctl reboot</code> commands are met with:

# systemctl suspend

Call to Suspend failed: Action suspend already in progress, refusing requested suspend operation.

# systemctl reboot

Call to Reboot failed: Action suspend already in progress, refusing requested reboot operation.

</syntaxhighlight>

If directly telling the kernel to suspend as root works:

# echo mem > /sys/power/state

</syntaxhighlight>

Then a long-running <code>pre-sleep.service</code> might be hanging the sleep. This can be verified with <code>systemctl list-jobs</code>:

# systemctl list-jobs

JOB UNIT TYPE STATE

12144 suspend.target start waiting

12149 pre-sleep.service start running

12145 systemd-suspend.service start waiting

12268 post-resume.target start waiting

12148 sleep.target start waiting

12269 post-resume.service start waiting

</syntaxhighlight>

Here, the <code>pre-sleep.service</code> is blocking and halting suspend. To see why, we can use <code>systemctl cat pre-sleep.service</code>:

# systemctl cat pre-sleep.service

# /etc/systemd/system/pre-sleep.service

[Unit]

Before=sleep.target

Description=Pre-Sleep Actions

[Service]

# <... Omitted Environment directives PATH, LOCALE_ARCHIVE, TZDIR ...>

ExecStart=/nix/store/yzf7cpiqzq49san2frijxsh160zjy6fp-unit-script-pre-sleep-start/bin/pre-sleep-start

Type=oneshot

[Install]

WantedBy=sleep.target

</syntaxhighlight>

In this case, the <code>pre-sleep-start</code> script referenced by <code>ExecStart</code> contained directives installed by the [[Displaylink]] package, that contained a flush operation which hung the suspend action. Starting <code>dlm.service</code> or running <code>sudo DisplayLinkManager</code> unblocks the script and made suspend work normally.

==== Cancelling an existing suspend action ====

An existing suspend operation that is hung may be interrupted using <code>'''systemctl cancel'''</code> in case reboots or internet access is needed.

== See also ==

@@ Line 30: / Line 30: @@
 <syntaxhighlight lang="nix">
-  systemd.services.your-service-name = {
+systemd.services.your-service-name = {
-    description = "Service description here";
+  description = "Service description here";
-    wantedBy = [ "post-resume.target" ];
+  wantedBy = [ "post-resume.target" ];
-    after = [ "post-resume.target" ];
+  after = [ "post-resume.target" ];
-    script = ''
+  script = ''
      echo "This should show up in the journal after resuming."
-    '';
+  '';
-    serviceConfig.Type = "oneshot";
+  serviceConfig.Type = "oneshot";
-  };
+};
 </syntaxhighlight>
@@ Line 48: / Line 48: @@
 Therefore, an example configuration could look like this:<syntaxhighlight lang="nix">
-/*
+// I'm hibernating into a logical volume that's also under LUKS. Pretty cool, right?
-  I'm hibernating into a logical volume that's also under LUKS. Pretty cool, right?
-*/
 swapDevices = [
@@ Line 59: / Line 57: @@
 boot.resumeDevice = "/dev/dm-7";
-</syntaxhighlight>Derived from a system with the following output from <code>swapon -s</code> :<syntaxhighlight>
+</syntaxhighlight>Derived from a system with the following output from <code>swapon -s</code> :<syntaxhighlight lang="text">Filename                                Type            Size           Used             Priority
-Filename                                Type            Size           Used             Priority
 /dev/dm-7                               partition       67108860       00
-/dev/zram0                              partition       32881148       032767
+/dev/zram0                              partition       32881148       032767</syntaxhighlight>
-</syntaxhighlight>
 Test and use hibernation with the following command:<syntaxhighlight lang="nix">
@@ Line 141: / Line 136: @@
 After finding out which component is causing unwanted wakeups you can use the sysfs id to find out the "vendor" and "device" fields:
-<syntaxhighlight lang="sh">
+<syntaxhighlight lang="console">
 $ cat /sys/class/pci_bus/0000:04/device/0000:04:00.0/vendor
 x1987
@@ Line 155: / Line 150: @@
 '';
 </syntaxhighlight>
+=== Suspend blocked by <code>pre-sleep.service</code> ===
+Sometimes, the system appears to suspend (Wi-Fi turns off, screen locks), but the hardware does not actually suspend, and all subsequent <code>systemctl suspend</code> or <code>systemctl reboot</code> commands are met with:
+<syntaxhighlight lang="console">
+# systemctl suspend
+Call to Suspend failed: Action suspend already in progress, refusing requested suspend operation.
+# systemctl reboot
+Call to Reboot failed: Action suspend already in progress, refusing requested reboot operation.
+</syntaxhighlight>
+If directly telling the kernel to suspend as root works:
+<syntaxhighlight lang="console">
+# echo mem > /sys/power/state
+</syntaxhighlight>
+Then a long-running <code>pre-sleep.service</code> might be hanging the sleep. This can be verified with <code>systemctl list-jobs</code>:
+<syntaxhighlight lang="console">
+# systemctl list-jobs
+JOB   UNIT                    TYPE  STATE
+suspend.target          start waiting
+pre-sleep.service       start running
+systemd-suspend.service start waiting
+post-resume.target      start waiting
+sleep.target            start waiting
+post-resume.service     start waiting
+</syntaxhighlight>
+Here, the <code>pre-sleep.service</code> is blocking and halting suspend. To see why, we can use <code>systemctl cat pre-sleep.service</code>:
+<syntaxhighlight lang="systemd">
+# systemctl cat pre-sleep.service
+# /etc/systemd/system/pre-sleep.service
+[Unit]
+Before=sleep.target
+Description=Pre-Sleep Actions
+[Service]
+# <... Omitted Environment directives PATH, LOCALE_ARCHIVE, TZDIR ...>
+ExecStart=/nix/store/yzf7cpiqzq49san2frijxsh160zjy6fp-unit-script-pre-sleep-start/bin/pre-sleep-start
+Type=oneshot
+[Install]
+WantedBy=sleep.target
+</syntaxhighlight>
+In this case, the <code>pre-sleep-start</code> script referenced by <code>ExecStart</code> contained directives installed by the [[Displaylink]] package, that contained a flush operation which hung the suspend action. Starting <code>dlm.service</code> or running <code>sudo DisplayLinkManager</code> unblocks the script and made suspend work normally.
+==== Cancelling an existing suspend action ====
+An existing suspend operation that is hung may be interrupted using <code>'''systemctl cancel'''</code> in case reboots or internet access is needed.
 == See also ==