Corrupted output on Haswell graphics

Hi all,

I just tested current on my Haswell notebook, and I'm not able to boot current
kernel and see the output uncorrupted.
To be clear this is Thinkpad X240 with 1366x760.

When booting recent snapshot 9.2.2015 the output is like very bad modeset is
applied. I "see" the kernel boot but scaled in upper 5% of the display and
the output is multiplied to fill the whole upper edge.

I tried to set:
hw.vga.textmode=1  # this produce no output at all
kern.vt.fb.default_mode="1366x768" # this does not change anything

Tried also some other resolutions as 1024x768, 800x600, 640x480. But seems it
does not change anything.

Regards,
Robert.