if too slow at login, computer turns unresponsive with a black screen
 

I recently installed Mint 17.3 (Rosa) with MATE on a T60 laptop.

The installation as such went without any notable obstacles.

However:

If I return to the computer after a while, then it has become impossible to log into through the terminal. It doesn't react on mouse movements - nor on any keys on the keyboard.

In fact, this occurs already if I hesitate slightly more than 60 seconds before I login.

(sshd is installed, and it is no problems to log in that way. But I do not know HOW to change the relevant parameters, or WHERE to find them, so in order to use the keyboard or see something on the screen, a shutdown or reboot is what remains for me.)

This all seems very much as an obvious bug to me. But being inexperienced and forgetful, I do not really know where to search for a solution or (even less) where to file a bug report.

I've tried with the search function here at LQ, and also with Google search too... but I do not find anything useful.
...alternatively: I do not understand enough to judge what to look after.

I've changed the (default) screensaver from "Blank screen" to "Floating GNOME", and put the time to 30 minutes for when the computer is to regard as idle, but that didn't solve this problem.

I did also uncheck the alternative "Dim display when idle" in the Power Management Preferences.

The other parameters there are:
Put computer to sleep when... NEVER
When laptop lid is closed: BLANK SCREEN
Put display to sleep when... NEVER

So, now the question are:

• What to do?
• What possible workarounds should I try next?
• Where do I check if anyone already has filed a bug report?

It looks more and more as if this is a real bug. Possibly with the MDM.

A workaround has been to switch on "Enable Timed Login".

But it's really no preferable solution.
Not in the long run, at least.

...or maybe more precisely with mdmwebkit.c.

When I'd found out that "mdm" seemed involved, it was easier to track down the culprit:
And suspicions pointed in the direction of /usr/share/mdm/distro.conf



There, I tried to remove one line at a time, starting with the first line (i.e. I commented out the first lines):
And I had luck!
The old greeter is of course dull, but working.

However, as it says in other configuration files, /etc/mdm/mdm.conf should probably be the preferred place for a patch instead.
With the chage above, the problem is solved.
If the line with "Greeter=..." is removed, then the problem is back.

Now, I can't go back in time and compare with the previous installed version of Mint and MATE - the disk is formatted.
But the file distro.conf looks similar to the one on my other laptop (although Cinnamon). Something may have changed between these two versions - most likely in the mdmwebkit

• 3.13.0-24-generic #47-Ubuntu SMP Fri May 2 23:30:00 UTC 2014
• 3.19.0-32-generic #37~14.04.1-Ubuntu SMP Thu Oct 22 09:37:25 UTC 2015

is your system running smoothly otherwise?

i'm not sure if a fullblown cinnamon desktop is the right choice for this matured thinkpad.

i don't think the mate version uses mdm? or at least not the webkit greeter?

also, is your RAM increased to at least 2, if not 4GB?

@onodoho, I thought he was using MATE on this, which would be just about right for this laptop.

@Manganus, excellent work tracing things down.
This thread seems to indicate you can either upgrade libwebkitgtk or just use the fix you did and switch greeters. (I don't know if you are a native English speaker, but your English is very good.)

Obviously, seeing as it is a known issue, I think you don't need to report a bug.

Hi ondoho!
I'm happy to see a response. :)
(Yes, I KNOW about the New Years Eve and festivities and stuff...)
Well, ...it's maybe too early to say, yet. I switched from Mint 17.0 (???) with MATE to 17.3 with MATE just a few days ago...
...but yes, it seems so.

Agree! ;) That was the initial reason for me to try out MATE on that mashine.
(Also Xfce is tested, but it didn't make that much of a difference - and I felt more at home with MATE.)

It seems as if it does. :D

Nope.
Delivered with 2 GB.


I didn't do much after installing Mint 17.3 [MATE].
I installed sshd, and updated some locals. And installed one server program, that I intend to run on this mashine.
...and then I copied default-user.svg, since that was an error reported in syslog, but that didn't help in THIS particular case. ;)

Thanks a lot, fellow!

It was exactly this kind of answer I was hoping for.

Then I think the issue is solved?

Yes, the matured Thinkpad does well. It's chiefly needed for "ssh -XC" and Chromium (32 bits).


In fact, I had to return to this thread in order to apply the same remedy to a much younger machine.
(T540, 4 cpu, 16 GB)
But I do find it remarkable that this (obvious!) bug remains in distro after distro, although I guess we are a quite small minority, "suffering" from it.

If it's of any interest, the soon-to-be-released Mint 18.2 has replaced MDM with LightDM, which may well resolve the problem (I read somewhere that one poster said it had, but I can't find that post again).

https://www.linuxmint.com/rel_sonya_mate_whatsnew.php