Unable to Suspend to RAM
Recently in Fedora 21 and 22 I noticed I was unable to suspend to RAM at the login manager screen and nobody logged in. I am using a Thinkpad T400 and LightDM.
With nobody logged in I was unable to suspend using
Fn+F4 or closing the lid. This is not a LightDM problem as I rebooted to the command line and repeated the results.
After logging in at run level 3, I ran
systemctl suspend and the laptop suspended immediately.
The logs provided no indication of pressing
Fn+F4 or closing the lid.
/etc/systemd/logind.conf should not need editing, I enabled the following:
HandleSuspendKey=suspend HandleLidSwitch=suspend HandleLidSwitchDocked=ignore
No change after restarting logind or rebooting.
After several hours of sleuthing I discovered two hurdles. In my
/etc/rc.d/rc.local I had the following:
if [ "`/sbin/lsmod | grep drm_kms_helper`" != "" ]; then echo N> /sys/module/drm_kms_helper/parameters/poll fi echo disable > /sys/firmware/acpi/interrupts/gpe11 2>/dev/null
While I had no comments in rc.local to remind me, I remember adding those directives because of mouse pointer freezing issues. I cannot say the options helped me as I still see the mouse pointer freeze at moments of intense disk activity. When this happens moving the mouse pointer is much like pushing strings.
After I commented out those lines in rc.local I then was able to suspend using
Fn+F4. Yet I still could not suspend by closing the lid. Eventually I added the following to
Finally I could suspend the T400 using both methods.