10.0_BETA intelfb/drm on x220 thinkpad

[Staffan Thomen <staffan%shangtai.net@localhost>]

Hey!

I was trying out the 10.0 beta on my x220 and it has so far been pretty 
good (setting the backlight brightness works again!), but a couple of 
things have come up;

I am using UEFI boot and have to set gop mode to 4 or the screen becomes 
garbled (green, presumably from the kernel messages, horizontal lines) 
but it works with 4 so that's fine but when the framebuffer and drm gets 
initialized things get worse;

[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[drm] Driver supports precise vblank timestamp query.
i915drmkms0: interrupting at msi5 vec 0 (i915drmkms0)
[drm] Initialized i915 1.6.0 20200114 for i915drmkms0 on minor 0
intelfb0 at i915drmkms0
[drm] DRM_I915_DEBUG enabled
[drm] DRM_I915_DEBUG_GEM enabled
intelfb0: framebuffer at 0xe0005000, size 1366x768, depth 32, stride 5504
{drm:netbsd:intel_cpu_fifo_underrun_irq_handler+0x64} *ERROR* CPU pipe A 
FIFO underrun
{drm:netbsd:intel_set_pch_fifo_underrun_reporting+0x14e} *ERROR* 
uncleared pch fifo underrun on pch transcoder A
{drm:netbsd:cpt_irq_handler+0x1dd} *ERROR* PCH transcoder A FIFO underrun
wsdisplay0 at intelfb0 kbdmux 1: console (default, vt100 emulation), 
using wskbd0

...and wsdisplay resets to a tiny resolution (huge text). X11 works just 
fine and seems accelerated.

wscons.conf is the default, but with changed encoding and a mapfile for 
a sane ctrl key position.

The other thing that crops up is occasional crashes when the system 
wakes up from sleep where xhci crashes with:

panic: kernel diagnostic assertion "sc->sc_suspender" failed: file 
"/usr/build/src/sys/dev/usb/xhci.c", line 920

The screen remains blank (text mode cursor in the corner), so this 
message is from savecore.

This may be related to me having a thinkpad dock that has usb devices. 
9.x did not crash like that though, despite the dock.

NetBSD roadwarrior 10.0_BETA NetBSD 10.0_BETA (GENERIC) #18: Sat Mar 25 
06:40:24 UTC 2023 
duck%power.shangtai.net@localhost:/usr/build/src/sys/arch/amd64/compile/obj/GENERIC 
amd64

Staffan