In this blog post I want to summarize my investigations about problems concerning suspend with my lenovo t460 notebook. (Note: This problem seems to also exists with the lenovo T460s notebooks. More information about debian on the t460 can be found here.)
(The informations here are verified with a debian testing installation with kernel version 4.4. The problems is reported by people using other distributions too.)
What is the problem and how can you reproduce it?
- If the device is on the AC, closing the lid causes the notebook to suspend. This works perfectly – in other words: The notebook wakes up after opening the lid and is usable.
- If the notebook is on battery, closing the lid causes the notebook to freeze. In other words: If I open the lid again, everything is frozen. Not only the UI but I’m also not able to change to TTY1, 2, ..
- Interestingly enough, manually suspending with systemctl suspend works without a glitch.
I reported this problem on the debian forums and the thinkpad subreddit.
There is an entry in the kernel bug tracker Bug 113551 – intel_pstate=no_hwp else Thinkpad T460s freezes on lid close on battery power. The bug entry indicates that the problem is also to be found kernel versions up to 4.5.0-rc6. It also looks like the source of the problem is found, patches are being tested. I also filed a debian bug entry for this problem as was suggested to my when asking in the debian IRC channel.
So it seems that newer kernel versions won’t have this problem. There is a workaround till this happens. You can add the intel_pstate=no_hwp parameter to the GRUB_CMDLINE_LINUX_DEFAULT section of the /etc/default/grub file. Attention: Don’t forget to run update-grub after every change to this file. Also: This may cause your notebook to use more power – the battery may empty itself faster.
I will try to update this blog post after more information, changes in the status of this problem occur. I maybe even try to patch the debian kernel with a patch and test if this helps to fix the suspend problem.
Update 2016-04-28: After upgrading to the Debian 4.5.1-1 (2016-04-14) x86_64 GNU/Linux kernel version, the suspend problem is gone. I can close the lid while being on batteries and the notebook is going into suspend and leaves it correctly.
Tags: kernel, lenovo, linux, open source, suspend, t460, t460s, Technology
Stefon's Blog 
March 26, 2016 at 11:06 pm |
[…] There is one problem with suspending. When the notebook is on the AC closing the lid causes the notebook to suspend. Opening the lid wakes it up. This works rather flawlessly. The problem is when the device works on batteries – in this case the device freezes when closing the lid. I have done some research and debugging on this problem and asked for support in a posting on the debian forums / I reported my problems in the thinkpad subreddit and got some interesting/informative answers. I’ll report if find some solution for this problem. Update: I’m summarizing my findings and updating new informations about this issue on a dedicated blog post. […]
March 27, 2016 at 12:17 am |
Just to document how helpful the guys and gals of the debian IRC channel (https://www.debian.org/support#irc) are:
23:25:13] |stefon| Hello everybody. I’m having a question concerning wether or not filing a bug to the debian bugtracker. I’m using a lenovo t460 notebook and there are two problems concerning suspend and the trackpoint. For both problems there exist kernel bug tracker entries. Does this mean that there is no need for a debian bug or would it be helpfull to file a new debian bug against the kernel I use? thx for the
[23:25:36] |stefon| help
[23:26:07] |chris_se| stefon, please check if there are debian bugs open for this, but if there really aren’t, then it might be good to file some
[23:26:13] |chris_se| just so that it can be tracked also within debian
[23:26:53] |stefon| I will check for that. If i really find no bug entry, you think i should create a new debian bug entry (of course with a link to the kernel bug entry)?
[23:26:55] |chris_se| just be sure to open them with the tags “upstream” (meaning: this affects upstream and not only debian) and provide a link to the kernel bugtracker
[23:27:14] |chris_se| if there really is no entry: yes, it’s a good idea to open a bug
[23:27:18] |stefon| perfect. thx for the help. I’ll do that
[23:27:29] |chris_se| just be sure to look for kernel bugs in the src:linux source package
[23:28:17] |chris_se| (see: |https://bugs.debian.org/cgi-bin/pkgreport.cgi?repeatmerged=no&src=linux| – warning: takes forever to load; if you get a 500 internal server error, try again a couple of minutes later)
[23:29:06] |chris_se| stefon, also, if somebody else already opened a kernel bug but there is no link to the upstream bug, send an email to that bug report and mention that link, that is always helpful
[23:29:29] |chris_se| the presence of a bug report in debian might help other debian users if they encounter the bug themselves
[23:30:05] |stefon| @chris_se I’ll have a look at the link you posted and create a new entry/enhance the existing one if there exists one
[23:30:23] |chris_se| just note that the debian kernel maintainers are very busy and there are so many things reported against the kernel that it might take a while until they get to it (if at all)
[23:31:11] |chris_se| anyway, hope that somebody resolves those bugs upstream soon
[23:32:12] |stefon| chris_se: I don’t expect them to make my problem their priority 🙂 as you say: an entry may help to track the problem. The bug entry in the kernel bug tracker indicate that there will be a fix upstream