Starting intel driver fails on boot

Hello.

A few months ago I sent an e-mail to this mailing list and reported 
about problems related to starting X on FreeBSD when using EFI mode. I 
"fixed" that problem by using the "scfb" driver from ports.

Today I, using "Xorg -configure", was playing around with the intel 
driver, since my Mac has a built-in Intel HD 3000 graphics card as well 
as a Radeon HD 6770M.

For some reason, when I attempt to start X with the intel driver, the 
screen freezes. However, if I start X using scfb and then manually load 
the i915kms kernel module, the system works perfectly fine until I leave 
X (at that time the screen freezes again).

When using the xorg.conf.new file generated by Xorg -configure, the 
system prefers to use the intel driver rather than the radeon driver 
(neither of which seem to work).

Taking a look at the output of dmesg -a from a verbose boot, I noted the 
following messages:
info: [drm] Initialized drm 1.1.0 20060810
drmn1: <Intel SandyBridge (M)> on vgapci1
vgapci1: attempting to allocate 1 MSI vectors (1 supported)
msi: routing MSI IRQ 268 to local APIC 2 vector 50
vgapci1: using IRQ 268 for MSI
info: [drm] MSI enabled 1 message(s)
info: [drm] AGP at 0xa0000000 256MB
iicbus0: <Philips I2C bus> on iicbb0 addr 0xff
iic0: <I2C generic I/O> on iicbus0
iic1: <I2C generic I/O> on iicbus1
iicbus2: <Philips I2C bus> on iicbb1 addr 0x0
iic2: <I2C generic I/O> on iicbus2
iic3: <I2C generic I/O> on iicbus3
iicbus4: <Philips I2C bus> on iicbb2 addr 0x0
iic4: <I2C generic I/O> on iicbus4
iic5: <I2C generic I/O> on iicbus5
iicbus6: <Philips I2C bus> on iicbb3 addr 0x0
iic6: <I2C generic I/O> on iicbus6
iic7: <I2C generic I/O> on iicbus7
iicbus8: <Philips I2C bus> on iicbb4 addr 0x0
iic8: <I2C generic I/O> on iicbus8
iic9: <I2C generic I/O> on iicbus9
iicbus10: <Philips I2C bus> on iicbb5 addr 0x0
iic10: <I2C generic I/O> on iicbus10
iic11: <I2C generic I/O> on iicbus11
iicbus12: <Philips I2C bus> on iicbb6 addr 0x0
iic12: <I2C generic I/O> on iicbus12
iic13: <I2C generic I/O> on iicbus13
iicbus14: <Philips I2C bus> on iicbb7 addr 0x0
iic14: <I2C generic I/O> on iicbus14
iic15: <I2C generic I/O> on iicbus15
info: [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
info: [drm] Driver supports precise vblank timestamp query.
info: [drm] Enabling RC6 states: RC6 off, RC6p off, RC6pp off
drmn1: taking over the fictitious range 0xa0000000-0xb0000000
info: [drm] Connector LVDS-1: get mode from tunables:
info: [drm]   - kern.vt.fb.modes.LVDS-1
info: [drm]   - kern.vt.fb.default_mode
info: [drm] Connector VGA-1: get mode from tunables:
info: [drm]   - kern.vt.fb.modes.VGA-1
info: [drm]   - kern.vt.fb.default_mode
info: [drm] Connector HDMI-A-1: get mode from tunables:
info: [drm]   - kern.vt.fb.modes.HDMI-A-1
info: [drm]   - kern.vt.fb.default_mode
info: [drm] Connector DP-1: get mode from tunables:
info: [drm]   - kern.vt.fb.modes.DP-1
info: [drm]   - kern.vt.fb.default_mode
fbd1 on drmn1
VT: Replacing driver "efifb" with new "fb".
info: [drm] Changing LVDS panel from (+hsync, +vsync) to (-hsync, -vsync)
info: [drm] Initialized i915 1.6.0 20080730
error: [drm:pid0:intel_lvds_enable] *ERROR* timed out waiting for panel 
to power off

Can someone please tell me what those messages (especially the last 4 
messages) mean?
Are they somehow related to the reason why the screen freezes when the 
intel driver is loaded during the launch of X?

Output of uname -a:
FreeBSD andersbo-mac.local 11.0-CURRENT FreeBSD 11.0-CURRENT #11 
r274793M: Fri Nov 21 16:26:45 CET 2014 
root_at_andersbo-mac.local:/usr/obj/usr/src/sys/KERNEL  amd64