Re: port-amd64/56740 (No display on Thinkpad T480 HMDI i915drmkms0 on 9.99.94 (working 9.99.92))

[David Brownlee <abs%absd.org@localhost>]

Behaviour is "different" with 9.99.97 (Thu May 26 20:17:40 UTC 2022 from nyftp)

Now the internal screen blanks when intelfb0 is attached if and
external monitor is connected. Unplugging HDMI screen restores display
to internal screen. External display remains blank at all times.

Reconnecting the external display leaves it blank but does not affect
the internal display at this point.

Interestingly, once xdm (slim) starts, switching ttyE0 shows a blank
display, again removing external display resolves this.

tail end of dmesg:

kern.module.path=/stand/amd64/9.99.97/modules
kern info: [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
kern info: [drm] Driver supports precise vblank timestamp query.
i915drmkms0: interrupting at msi6 vec 0 (i915drmkms0)
i915drmkms0: notice: Failed to load DMC firmware i915/kbl_dmc_ver1_04.bin. Disab
ling runtime power management.
kern info: [drm] Initialized i915 1.6.0 20200114 for i915drmkms0 on minor 0
iwm0: hw rev 0x230, fw ver 22.361476.0, address 38:ba:f8:10:be:77
intelfb0 at i915drmkms0
kern info: [drm] DRM_I915_DEBUG enabled
kern info: [drm] DRM_I915_DEBUG_GEM enabled
intelfb0: framebuffer at 0xa0040000, size 1920x1080, depth 32, stride 7680
warning: /usr/src/sys/external/bsd/drm2/dist/drm/i915/display/intel_hdmi.c:788:
WARN_ON(ret)wsdisplay0 at intelfb0 kbdmux 1: console (default, vt100 emulation),
 using wskbd0
wsmux1: connecting to wsdisplay0
warning: /usr/src/sys/external/bsd/drm2/dist/drm/i915/display/intel_hdmi.c:788:
WARN_ON(ret)acpibat1: normal capacity on 'charge state'
warning: /usr/src/sys/external/bsd/drm2/dist/drm/i915/display/intel_hdmi.c:788:
WARN_ON(ret)sd0(umass0:0:0:0):  Check Condition on CDB: 0x00 00 00 00 00 00
    SENSE KEY:  Not Ready
     ASC/ASCQ:  Medium Not Present
wsdisplay0: screen 1 added (default, vt100 emulation)
wsdisplay0: screen 2 added (default, vt100 emulation)
wsdisplay0: screen 3 added (default, vt100 emulation)
wsdisplay0: screen 4 added (default, vt100 emulation)
sd0(umass0:0:0:0):  Check Condition on CDB: 0x00 00 00 00 00 00
    SENSE KEY:  Not Ready
     ASC/ASCQ:  Medium Not Present
warning: /usr/src/sys/external/bsd/drm2/dist/drm/i915/display/intel_hdmi.c:788:
WARN_ON(ret)warning: /usr/src/sys/external/bsd/drm2/dist/drm/i915/display/intel_
hdmi.c:788: WARN_ON(ret)warning: /usr/src/sys/external/bsd/drm2/dist/drm/i915/di
splay/intel_hdmi.c:788: WARN_ON(ret)warning: /usr/src/sys/external/bsd/drm2/dist
/drm/i915/display/intel_hdmi.c:788: WARN_ON(ret)