I just installed Ubuntu 14.04 on my Fujitsu Lifebook U772 after a long hiatus with Opensuse and after the install, it appears that pm-suspend works out of the box. A few days of setting up later, however, suspend stopped working, with the menu option of Suspend only resulting in the screen momentarily going black then returning to the lock screen.

I manually tried to suspend the machine from a terminal using sudo pm-suspend but still to no avail. I started looking over the pm-suspend log at /var/log/pm-suspend.log, and I noticed something strange:

Running hook /usr/lib/pm-utils/sleep.d/00logging suspend suspend:

Linux deathbook 3.13.0-30-generic #55-Ubuntu SMP Fri Jul 4 21:40:53 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Module                  Size  Used by

vboxpci                23194  0 

vboxnetflt             27613  0 

vboxnetadp             25670  0 

vboxdrv               339502  3 vboxnetadp,vboxnetflt,vboxpci

pci_stub               12622  1 

ctr                    13049  1 

ccm                    17773  1 

bnep                   19624  2 

rfcomm                 69160  0 

bluetooth             395423  10 bnep,rfcomm

binfmt_misc            17468  1 

nls_iso8859_1          12713  1 

arc4                   12608  2 

iwldvm                232285  0 

intel_rapl             18773  0 

uvcvideo               80885  0 

hid_generic            12548  0 

x86_pkg_temp_thermal    14205  0 

videobuf2_vmalloc      13216  1 uvcvideo

intel_powerclamp       14705  0 

videobuf2_memops       13362  1 videobuf2_vmalloc

coretemp               13435  0 

videobuf2_core         40664  1 uvcvideo

videodev              134688  2 uvcvideo,videobuf2_core

kvm_intel             143060  0 

mac80211              626557  1 iwldvm

usbhid                 52570  0 

kvm                   451511  1 kvm_intel

i2400m_usb             36521  0 

hid                   106148  2 hid_generic,usbhid

i2400m                107913  1 i2400m_usb

wimax                  34704  1 i2400m

crct10dif_pclmul       14289  0 

snd_hda_codec_hdmi     46207  1 

crc32_pclmul           13113  0 

ghash_clmulni_intel    13216  0 

aesni_intel            55624  2 

snd_hda_codec_realtek    61438  1 

aes_x86_64             17131  1 aesni_intel

i915                  783703  4 

snd_hda_intel          52355  3 

snd_hda_codec         192906  3 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_intel

lrw                    13286  1 aesni_intel

iwlwifi               169932  1 iwldvm

snd_hwdep              13602  1 snd_hda_codec

snd_pcm               102099  3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel

gf128mul               14951  1 lrw

drm_kms_helper         53081  1 i915

snd_page_alloc         18710  2 snd_pcm,snd_hda_intel

snd_seq_midi           13324  0 

glue_helper            13990  1 aesni_intel

drm                   303102  5 i915,drm_kms_helper

cfg80211              484040  3 iwlwifi,mac80211,iwldvm

ablk_helper            13597  1 aesni_intel

snd_seq_midi_event     14899  1 snd_seq_midi

cryptd                 20359  3 ghash_clmulni_intel,aesni_intel,ablk_helper

snd_rawmidi            30144  1 snd_seq_midi

i2c_algo_bit           13413  1 i915

snd_seq                61560  2 snd_seq_midi_event,snd_seq_midi

snd_seq_device         14497  3 snd_seq,snd_rawmidi,snd_seq_midi

snd_timer              29482  2 snd_pcm,snd_seq

mei_me                 18627  0 

mei                    82276  1 mei_me

snd                    69238  17 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi

rtsx_pci_ms            18151  0 

soundcore              12680  1 snd

memstick               16966  1 rtsx_pci_ms

joydev                 17381  0 

mac_hid                13205  0 

lpc_ich                21080  0 

fujitsu_laptop         18947  0 

video                  19476  1 i915

serio_raw              13462  0 

parport_pc             32701  0 

ppdev                  17671  0 

lp                     17759  0 

parport                42348  3 lp,ppdev,parport_pc

rtsx_pci_sdmmc         23274  0 

e1000e                254433  0 

psmouse               102222  0 

ahci                   25819  5 

libahci                32168  1 ahci

rtsx_pci               45956  2 rtsx_pci_ms,rtsx_pci_sdmmc

ptp                    18933  1 e1000e

pps_core               19382  1 ptp

             total       used       free     shared    buffers     cached

Mem:       3905144    2586540    1318604     356556       6452     531508

-/+ buffers/cache:    2048580    1856564

Swap:      8190472          0    8190472

/usr/lib/pm-utils/sleep.d/00logging suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/00powersave suspend suspend:

/usr/lib/pm-utils/sleep.d/00powersave suspend suspend: success.



Running hook /etc/pm/sleep.d/10_grub-common suspend suspend:

/etc/pm/sleep.d/10_grub-common suspend suspend: success.



Running hook /etc/pm/sleep.d/10_unattended-upgrades-hibernate suspend suspend:

/etc/pm/sleep.d/10_unattended-upgrades-hibernate suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/50unload_alx suspend suspend:

/usr/lib/pm-utils/sleep.d/50unload_alx suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/60_wpa_supplicant suspend suspend:

Selected interface 'wlan0'

OK

/usr/lib/pm-utils/sleep.d/60_wpa_supplicant suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/75modules suspend suspend:

Unloading kernel module vboxdrv...Done.

/usr/lib/pm-utils/sleep.d/75modules suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/90clock suspend suspend:

/usr/lib/pm-utils/sleep.d/90clock suspend suspend: not applicable.



Running hook /usr/lib/pm-utils/sleep.d/94cpufreq suspend suspend:

/usr/lib/pm-utils/sleep.d/94cpufreq suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/95anacron suspend suspend:

stop: Unknown instance: 

/usr/lib/pm-utils/sleep.d/95anacron suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/95hdparm-apm suspend suspend:

/usr/lib/pm-utils/sleep.d/95hdparm-apm suspend suspend: not applicable.



Running hook /usr/lib/pm-utils/sleep.d/95led suspend suspend:

/usr/lib/pm-utils/sleep.d/95led suspend suspend: not applicable.



Running hook /usr/lib/pm-utils/sleep.d/98video-quirk-db-handler suspend suspend:

Kernel modesetting video driver detected, not using quirks.

/usr/lib/pm-utils/sleep.d/98video-quirk-db-handler suspend suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/99video suspend suspend:

kernel.acpi_video_flags = 0

/usr/lib/pm-utils/sleep.d/99video suspend suspend: success.



Running hook /etc/pm/sleep.d/novatel_3g_suspend suspend suspend:

/etc/pm/sleep.d/novatel_3g_suspend suspend suspend: success.



Fri Jul 11 07:17:01 PHT 2014: performing suspend

sh: echo: I/O error

Fri Jul 11 07:17:03 PHT 2014: Awake.

Fri Jul 11 07:17:03 PHT 2014: Running hooks for resume

Running hook /etc/pm/sleep.d/novatel_3g_suspend resume suspend:

/etc/pm/sleep.d/novatel_3g_suspend resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/99video resume suspend:

/usr/lib/pm-utils/sleep.d/99video resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/98video-quirk-db-handler resume suspend:

/usr/lib/pm-utils/sleep.d/98video-quirk-db-handler resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/95led resume suspend:

/usr/lib/pm-utils/sleep.d/95led resume suspend: not applicable.



Running hook /usr/lib/pm-utils/sleep.d/95hdparm-apm resume suspend:



/dev/sda:

 setting Advanced Power Management level to 0xfe (254)

 APM_level  = 254



/dev/sdb:

 setting Advanced Power Management level to 0xfe (254)

 APM_level  = 254

/usr/lib/pm-utils/sleep.d/95hdparm-apm resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/95anacron resume suspend:

/usr/lib/pm-utils/sleep.d/95anacron resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/94cpufreq resume suspend:

/usr/lib/pm-utils/sleep.d/94cpufreq resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/90clock resume suspend:

/usr/lib/pm-utils/sleep.d/90clock resume suspend: not applicable.



Running hook /usr/lib/pm-utils/sleep.d/75modules resume suspend:

Reloaded unloaded modules.

/usr/lib/pm-utils/sleep.d/75modules resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/60_wpa_supplicant resume suspend:

Selected interface 'wlan0'

OK

/usr/lib/pm-utils/sleep.d/60_wpa_supplicant resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/50unload_alx resume suspend:

/usr/lib/pm-utils/sleep.d/50unload_alx resume suspend: success.



Running hook /etc/pm/sleep.d/10_unattended-upgrades-hibernate resume suspend:

/etc/pm/sleep.d/10_unattended-upgrades-hibernate resume suspend: success.



Running hook /etc/pm/sleep.d/10_grub-common resume suspend:

/etc/pm/sleep.d/10_grub-common resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/00powersave resume suspend:

/usr/lib/pm-utils/sleep.d/00powersave resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/00logging resume suspend:

/usr/lib/pm-utils/sleep.d/00logging resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/000record-status resume suspend:

/usr/lib/pm-utils/sleep.d/000record-status resume suspend: success.



Running hook /usr/lib/pm-utils/sleep.d/000kernel-change resume suspend:

/usr/lib/pm-utils/sleep.d/000kernel-change resume suspend: success.



Fri Jul 11 07:17:04 PHT 2014: Finished.

More specifically, it was along these lines (this is the part where the system actually performs the suspend):

Fri Jul 11 07:17:01 PHT 2014: performing suspend

sh: echo: I/O error

Fri Jul 11 07:17:03 PHT 2014: Awake.

Fri Jul 11 07:17:03 PHT 2014: Running hooks for resume

Running hook /etc/pm/sleep.d/novatel_3g_suspend resume suspend:

/etc/pm/sleep.d/novatel_3g_suspend resume suspend: success.

I think the weird part here is the sh: echo: I/O error that shows up every time the system does a suspend, as you can see, the system immediately awakens after the error.

I've tried a lot of workarounds that include the following:

• Disabling Virtualbox's vboxdrv modules as I have read that they sometimes interfere with a host machine's ability to suspend


• Disabling all devices that could wake the system in /proc/acpi/wakeup


• Replacing the errors=remount ro option for / in /etc/fstab to errors=continue

Despite all of those the problem still persists. Could it be an issue with the kernel? Back when I was still using Opensuse 12.3 I was stuck in kernel 3.7, and now here in Ubuntu 14.04 I'm using kernel 3.13. Though I kind of doubt that the kernel might be the issue since 3.13 came out of the box and suspend still worked at that time.

UPDATE:

I've found that the cause for the echo that causes the I/O fail is in line 321 of /usr/lib/pm-utils/pm-functions. I got this by turning on verbose logging and debugging for pm-suspend, and disabling all hooks (by moving them temporarily to another directory).

This is the line in question:

 do_suspend() { echo -n "mem" >/sys/power/state; }

As I understand it, this echo is crucial because it's the interface between pm-suspend and the low-level functions in the kernel that handle suspends. The issue now is why would an I/O error occur at that moment. I'll try to manually perform the command on a terminal and see if an I/O error still occurs.