Problem starting X after upgrade to 4.4

[Tony Power]

> I regularly test Intel graphics on a Core 2/i965 laptop but your chipset
> is
> even older than that.
>
> The drm/i915 driver wasn't updated in one step from 4.2 to 4.4. You could
> try
> to use git to bisect which particular set of changes broke it. We then
> would
> have more chances to find out what is going wrong.
>
> Another thing you could try is to update to DragonFly master where the
> driver
> has once again be updated. With luck you could have better results.
>
> --
> Francois Tigeot
>
Hi Francois, I upgraded to Dragonfly master (now running DragonFly
v4.5.0.443.gf6fab-DEVELOPMENT) and installed xf86-video-intel29 from
dports. The problem still persists unfortunately.

There is a slight difference in the error description logged in
/var/log/messages , but apart from that the behaviour is the same, the
screen blanks out and the computer must be power cycled.

Feb  7 14:46:50 scabb kernel: info: [drm] failed to find VBIOS tables
Feb  7 14:46:50 scabb kernel: tunable drm.video.VGA-1 is not set
Feb  7 14:46:51 scabb kernel: vblank wait timed out on crtc 1
Feb  7 14:46:51 scabb kernel: MAPPABLE_END VS END 0000000010000000
0000000010000000

Feb  3 21:58:38 scabb kernel: info: [drm] failed to find VBIOS tables
Feb  3 21:58:38 scabb kernel: looking up kenv for "drm.video.vga1"
Feb  3 21:58:38 scabb kernel: didn't find value for kenv drm.video.vga1
Feb  3 21:58:38 scabb kernel: MAPPABLE_END VS END 0000000010000000
0000000010000000

Not an issue for me anyway, I am happy to use the VESA driver. Thanks for
the suggestion.