[ltp] X1 Carbon (2nd gen) not resuming from suspend

[Xavier Fernández i Marín]

Dear all,

First of all, let me introduce myself as a fairly happy newcomer to
Thinkpads. I purchased a month ago an X1 Carbon (2nd generation) and
installed Gentoo after having made copies of the original windows
installation. Everything is working pretty well, except for suspension
(well, maybe also the fact that sound is quite loud, but that would be
another story).

Technically I have to say that the computer enters into suspension
correctly (/var/log/hibernate.log says so), but it is not able to resume.

So this is the list of evidences and conclusions that I have arrived to:

  - BIOS is updated [1]

  - s2ram doesn't work, in any of its suggested command line options, also
    even starting with a minimal setting and not loading any modules from
    the grub menu.

  - hibernate-ram doesn't work neither (ever removing all modules,
    including thinkpad_acpi).

  - A live USB session with Ubuntu 14.04 is able to suspend and resume
    correctly.

  - I have read carefully a previous message in the list but with no luck.
    (http://linux-thinkpad.10952.n7.nabble.com/Gen-2-Haswell-X1-Carbon-suspend-to-RAM-hang-td21039.html),


I'm lost because the computer is able to resume using a live Ubuntu 14.04
distribution. This means that the machine is able to resume (so I have to
discard BIOS issues, or any weird BIOS configuration setting that I may
have used).

Does anyone else have any idea of what else can I do? Is there something in
the kernel that has to be configured as module so that it is unloaded
before suspension? 


Thank you very much.



[1] Bios information
BIOS Information
        Vendor: LENOVO
        Version: GRET38WW (1.15 )
        Release Date: 05/29/2014
        Address: 0xE0000
        Runtime Size: 128 kB
        ROM Size: 8192 kB
        Characteristics:
          PCI is supported
          PNP is supported
          BIOS is upgradeable
          BIOS shadowing is allowed
          Boot from CD is supported
          Selectable boot is supported
          ACPI is supported
          USB legacy is supported
          BIOS boot specification is supported
          Targeted content distribution is supported
          UEFI is supported
       BIOS Revision: 1.15
       Firmware Revision: 1.13

-- 
-  Xavier  -