Comment # 13 on bug 917411 from macias -

> Did you have a working kernel beforehand?

Yes, the same machine on previous installation. I installed OS 13.2 as soon as
it was launched, no problem for ~4 months, then I reinstalled it, and give or
take few packages, the only major difference is now I used encrypted LVM
partition for root. Before reinstall, it worked flawlessly, now it freezes.

> I guess you misunderstood SysRq.  What's here referred to is the
> "Magic SysRq" keys.  The key combo Alt+SysRq+something (on a
> laptop, it's often with Alt+Fn+Print+something) is captured
> directly by kernel for special tasks.  So it must work no matter
> which desktop GUI is used.

Should it work when computer is normally working? Because it does not work, I
tested it. I get some output only in console, in GUI it was like I didn't press
it at all.

> Note that not all sysrq key combos are enabled as default, as
> already mentioned.  This has to be enabled via sysctl.conf stuff.

Already done.

> BTW, are you using BTRFS? 

No, no. Encryption, LVM, ext3/ext4, that's all.