kern/56608: i915drmkms0: info: [drm] Cannot find any crtc or sizes

[prlw1%cam.ac.uk@localhost]

>Number:         56608
>Category:       kern
>Synopsis:       i915drmkms0: info: [drm] Cannot find any crtc or sizes
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jan 06 15:45:00 +0000 2022
>Originator:     Patrick Welche
>Release:        NetBSD-9.99.93/amd64 of 1 Jan 2022
>Organization:
>Environment:
i915drmkms0 at pci0 dev 2 function 0: Intel Ivy Bridge Integrated Graphics Device (rev. 0x09)

>Description:
An old Ivy Bridge box seems unhappy with the new drm code, complaining that:

kern info: [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
kern info: [drm] Driver supports precise vblank timestamp query.
i915drmkms0: interrupting at msi4 vec 0 (i915drmkms0)
kern info: [drm] Initialized i915 1.6.0 20200114 for i915drmkms0 on minor 0
i915drmkms0: info: [drm] Cannot find any crtc or sizes
kern info: [drm] DRM_I915_DEBUG enabled
kern info: [drm] DRM_I915_DEBUG_GEM enabled
i915drmkms0: info: [drm] Cannot find any crtc or sizes


Before the change, with a 9.99.2 kernel of 30 November:

kern info: [drm] Memory usable by graphics device = 2048M
kern info: [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
kern info: [drm] Driver supports precise vblank timestamp query.
kern info: [drm] failed to find VBIOS tables
i915drmkms0: interrupting at msi4 vec 0 (i915drmkms0)
intelfb0 at i915drmkms0
intelfb0: framebuffer at 0xe0064000, size 1280x1024, depth 32, stride 5120
kern error: [drm:(../../../../external/bsd/drm2/dist/drm/i915/intel_fifo_underrun.c:229)cpt_set_fifo_underrun_reporting] *ERROR* uncleared pch fifo underrun on pch transcoder A
kern error: [drm:(../../../../external/bsd/drm2/dist/drm/i915/intel_fifo_underrun.c:380)intel_pch_fifo_underrun_irq_handler] *ERROR* PCH transcoder A FIFO underrun
kern error: [drm:(../../../../external/bsd/drm2/dist/drm/i915/intel_fifo_underrun.c:175)ivybridge_set_fifo_underrun_reporting] *ERROR* uncleared fifo underrun on pipe A
kern error: [drm:(../../../../external/bsd/drm2/dist/drm/i915/intel_fifo_underrun.c:362)intel_cpu_fifo_underrun_irq_handler] *ERROR* CPU pipe A FIFO underrun
wsdisplay0 at intelfb0 kbdmux 1

>How-To-Repeat:

>Fix: