Minetest stop responding to keyboard and mouse inputs

[elettrico]

Hi,
I'm using minetest 0.4.16 on linux mint on my laptop, with opengl drivers.
When I play it in windowed mode (800x600) I experience a very high cpu use (and Intel Core i3-2350M @ 2.30GHz), but I can play with no problem (until my laptop reach 80 celsius :P).
When I play it in fullscreen mode (800x600 with opengl driver) I can play with full range view enabled without cpu overheating, but if stop playing for 5 or 10 minutes, by pressing ESC or simply by leaving the game run, at some point the game "freeze while still running": I get the mouse pointer at the center of the screen, I see the game running (time change, for example) but it stop responding to keyboard and mouse inputs.
At this point it start to use a lot of cpu, dtime_jitter start grow > 60% and have spikes (sometime > 100%) and the only way for me to regain control is to kill the minetest process and restart it.
I experienced this problem in local games and lan games.
There is a photo of the screen during a freeze (I'm connected to my minetest server, in the same lan as the client): https://www.dropbox.com/s/ukacrpd4fv0vx ... 5.jpg?dl=0
Nothing appears in debug.txt.

Does anyone have suggestion? Is there any configuration to let me see what's happening? Any "deep" debug log? Any possibility to activate a rendering log to see if it's a graphics driver problem (anyway, I don't have problems with other opengl games)

my graphics controller:
PCI (sysfs)
*-display
description: VGA compatible controller
product: 2nd Generation Core Processor Family Integrated Graphics Controller [8086:116]
vendor: Intel Corporation [8086]
physical id: 2
bus info: pci@0000:00:02.0
version: 09
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:25 memory:c0000000-c03fffff memory:b0000000-bfffffff ioport:3000(size=64)

Thanks

[lisacvuk]

It's a laptop? I'm guessing after some time it enters powersaving mode, which does this.

[elettrico]

So when linux try to blank the screen it breaks minetest fullscreen mode?
I'll check.