After observing a lot I noticed that alongside with the intermittent failure also had an error message "PM: Device 00:06 failed to resume: error -19" that always appeared for a second before hibernate/suspend.
Furthermore sometimes the desktop have returned and whenever I moved the mouse (touchpad) I had an endless list of messages in syslog ([drm: hsw_unclaimed_reg_clear] * ERROR * Unknown unclaimed register before writing to 70088). This led me to investigate the touchpad. Researching I found mention in various forums about the touchpad on some SONY VAIOs notebooks where was suggested inserting the following kernel parameter in /etc/default/grub. GRUB_CMDLINE_LINUX = "i8042.nopnp" After that run sudo update-grub and reboot. Hardly believe it, but thereafter there were no more error messages and the notebook hibernate/suspend and resume without problem. I'm using now kernel 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux (trusty proposed) fglrx 14.20(beta) (.deb packages created using ATI installer using orientations from "http://wiki.cchtml.com/index.php/Ubuntu_Trusty_Installation_Guide#Removing_Catalyst.2Ffglrx";) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1305109 Title: [Dell Inc. Vostro 3555] /resume failure [non-free: wl fglrx] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1305109/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
