11.0_RC1: i915drmkms crashes hard on Zotac Nano CI327 unless 'boot -x' specified

[Henryk Paluch <hpaluch%seznam.cz@localhost>]

Hello!

From 11.0_BETA (and later including RC1) I'm facing weird issue with 
i915drmkms driver:

1. when booting in default mode - kernel crashes hard at activating 
i915drmkms - both disk and Blue Ray activity completely ceases. Only 
power-cycle (holding power button for 4s) responds and allows reboot

2. even more weird is workaround: just specifying trace mode with "boot 
-x" resolves this issue and system boots and works without issues

Here are more details on affected system: Zotac Nano CI327 with 
integrated Intel HD Graphics 500

nbsd-zotac$ uname -a

NetBSD nbsd-zotac.example.com 11.0_RC1 NetBSD 11.0_RC1 (GENERIC) #0: Fri 
Feb  6 08:24:25 UTC 2026 
mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64

nbsd-zotac$ pcictl pci0 list -N
000:00:0: Intel Apollo Lake Host Bridge (host bridge, revision 0x0b) [pchb0]
000:02:0: Intel Apollo Lake Graphics (12EU) (VGA display, revision 0x0b) 
[i915drmkms0]
000:13:2: Intel Apollo Lake Fast SPI (miscellaneous serial bus, revision 
0x0b)
000:14:0: Intel Apollo Lake HD Audio (mixed mode multimedia, HD Audio 
1.0, revision 0x0b) [hdaudio0]
000:15:0: Intel Apollo Lake TXE HECI1 (miscellaneous communications, 
revision 0x0b)
000:18:0: Intel Apollo Lake SATA (SATA mass storage, AHCI 1.0, revision 
0x0b) [ahcisata0]
000:19:0: Intel Apollo Lake PCIe A0 (PCI bridge, revision 0xfb) [ppb0]
000:19:2: Intel Apollo Lake PCIe A2 (PCI bridge, revision 0xfb) [ppb1]
000:20:0: Intel Apollo Lake PCIe B1 (PCI bridge, revision 0xfb) [ppb2]
000:21:0: Intel Apollo Lake USB Host (xHCI) (USB serial bus, xHCI, 
revision 0x0b) [xhci0]
000:26:0: Intel product 5ac8 (miscellaneous serial bus, revision 0x0b)
000:28:0: Intel Apollo Lake eMMC (SD Host Controller system, interface 
0x01, revision 0x0b) [sdhc0]
000:30:0: Intel product 5ad0 (SD Host Controller system, interface 0x01, 
revision 0x0b) [sdhc1]
000:31:0: Intel Apollo Lake LPC (ISA bridge, revision 0x0b) [pcib0]
000:31:1: Intel Apollo Lake SMBus (SMBus serial bus, revision 0x0b) 
[ichsmb0]
001:00:0: Intel Dual Band Wireless AC 3165 (miscellaneous network, 
revision 0x81) [iwm0]
002:00:0: Realtek Semiconductor 8168/8111 10/100/1000 Ethernet (ethernet 
network, revision 0x0c) [re0]
003:00:0: Realtek Semiconductor 8168/8111 10/100/1000 Ethernet (ethernet 
network, revision 0x0c) [re1]

Disclaimer: no kernel dump and no serial port available - I'm unable to 
collect any details regarding crash

Anybody else encountering same issue?

Regards
  --Henryk Paluch

P.S. Below is related output of dmesg when booted in trace mode with 
"boot -x":

nbsd-zotac$ dmesg -t | grep 915

efi: 0x7a20d100 49152e77-1ada-4764-b7a2-7afefed95e8b
i915drmkms0 at pci0 dev 2 function 0: Intel Apollo Lake Graphics (12EU) 
(rev. 0x0b)
i915drmkms0: WARNING: power management not supported
i915drmkms0: map 5 failed
i915drmkms0 {drm:netbsd:i915_driver_probe+0x322} WOPCM: 1024K
i915drmkms0 {drm:netbsd:intel_uc_init_early+0x8f} enable_guc=0 (guc:no 
submission:no huc:no)
{drm:netbsd:i915_gem_init_early+0x67} fake context support initialized
i915drmkms0 {drm:netbsd:intel_uncore_init_mmio+0x22a} unclaimed mmio 
detected on uncore init, clearing
{drm:netbsd:i915_ggtt_probe_hw+0x4ce} GGTT size = 4096M
{drm:netbsd:i915_ggtt_probe_hw+0x4ec} GMADR size = 256M
{drm:netbsd:i915_ggtt_probe_hw+0x515} DSM size = 0M
{drm:netbsd:i915_driver_probe+0x634} Initialized 3 GT workarounds on global
i915drmkms0: interrupting at msi6 vec 0 (i915drmkms0)
[drm] Finished loading DMC firmware i915/bxt_dmc_ver1_07.bin (v1.7)
i915drmkms0: notice: RC6 and powersaving disabled by BIOS
[drm] Initialized i915 1.6.0 20200114 for i915drmkms0 on minor 0
intelfb0 at i915drmkms0
i915 device info: pciid=0x5a85 rev=0x0b platform=BROXTON 
(subplatform=0x0) gen=9
i915 device info: engines: 47
i915 device info: gen: 9
i915 device info: gt: 0
i915 device info: iommu: n/a
i915 device info: memory-regions: 5
i915 device info: page-sizes: 11000
i915 device info: platform: BROXTON
i915 device info: ppgtt-size: 48
i915 device info: ppgtt-type: 2
i915 device info: is_mobile: no
i915 device info: is_lp: yes
i915 device info: require_force_probe: no
i915 device info: is_dgfx: no
i915 device info: has_64bit_reloc: yes
i915 device info: gpu_reset_clobbers_display: no
i915 device info: has_reset_engine: yes
i915 device info: has_fpga_dbg: yes
i915 device info: has_global_mocs: no
i915 device info: has_gt_uc: yes
i915 device info: has_l3_dpf: no
i915 device info: has_llc: no
i915 device info: has_logical_ring_contexts: yes
i915 device info: has_logical_ring_elsq: no
i915 device info: has_logical_ring_preemption: yes
i915 device info: has_pooled_eu: no
i915 device info: has_rc6: yes
i915 device info: has_rc6p: no
i915 device info: has_rps: yes
i915 device info: has_runtime_pm: yes
i915 device info: has_snoop: yes
i915 device info: has_coherent_ggtt: no
i915 device info: unfenced_needs_alignment: no
i915 device info: hws_needs_physical: no
i915 device info: cursor_needs_physical: no
i915 device info: has_csr: yes
i915 device info: has_ddi: yes
i915 device info: has_dp_mst: yes
i915 device info: has_dsb: no
i915 device info: has_dsc: no
i915 device info: has_fbc: no
i915 device info: has_gmch: no
i915 device info: has_hdcp: yes
i915 device info: has_hotplug: yes
i915 device info: has_ipc: yes
i915 device info: has_modular_fia: no
i915 device info: has_overlay: no
i915 device info: has_psr: yes
i915 device info: overlay_needs_physical: no
i915 device info: supports_tv: no
i915 device info: slice total: 1, mask=0001
i915 device info: subslice total: 2
i915 device info: slice0: 2 subslices, mask=00000006
i915 device info: EU total: 12
i915 device info: EU per subslice: 6
i915 device info: has slice power gating: no
i915 device info: has subslice power gating: yes
i915 device info: has EU power gating: yes
i915 device info: CS timestamp frequency: 19200 kHz
[drm] DRM_I915_DEBUG enabled
[drm] DRM_I915_DEBUG_GEM enabled