X11 on Lenovo T430

[Havard Eidnes <he%uninett.no@localhost>]

Hi,

I'm running netbsd-7 code on my new Lenovo T430 laptop.  I'm
using code from November 27 at the moment, with the DRM/KMS
kernel, and there are a few glitches:

1) Sometimes the rendering of images e.g. in a web browser
   (firefox) is mangled / "interlaced" (not sure how to best
   describe it).  Sometimes causing a re-paint fixes the glitch,
   sometimes it doesn't (by the looks of it).

2) Sometimes X11 appears to hang, and I get these messages in my
   kernel message buffer:

drm: stuck on blitter ring
drm: GPU HANG: ecode 2:0x87d0fff5, reason: Ring hung, action: reset
drm: GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
drm: Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel
drm: drm/i915 developers can then reassign to the right component if it's not a kernel issue.
drm: The gpu crash dump is required to analyze gpu hangs, so please always attach it.
drm: GPU crash dump saved to /sys/class/drm/card0/error
i915drmkms0: interrupting at ioapic0 pin 16 (pci0@pci:0000:00:02.0)
drm: Enabling RC6 states: RC6 on, RC6p on, RC6pp off

(There's no GPU crash dump that I can find anywhere...)

The hardware is probed by the kernel as:

i915drmkms0 at pci0 dev 2 function 0: Intel Ivy Bridge Integrated Graphics Device (rev. 0x09)
drm: Memory usable by graphics device = 2048M
drm: Supports vblank timestamp caching Rev 2 (21.10.2013).
drm: Driver supports precise vblank timestamp query.
i915drmkms0: interrupting at ioapic0 pin 16 (i915)
drm: GMBUS [i915 gmbus dpb] timed out, falling back to bit banging on pin 5
intelfb0 at i915drmkms0
i915drmkms0: info: registered panic notifier
intelfb0: framebuffer at 0xffff800118fe6000, size 1600x900, depth 32, stride 6400
wsdisplay0 at intelfb0 kbdmux 1: console (default, vt100 emulation), using wskbd0
wsmux1: connecting to wsdisplay0

and pcictl says:

000:02:0: Intel Ivy Bridge Integrated Graphics Device (VGA display, revision 0x09)
or
000:02:0: 0x01668086 (0x03000009)

I'm about to update to newer netbsd-7 code (just updated my
source tree), unless someone tells me "no-no, don't do that".

Regards,

- Håvard