freebsd r265915 VT Rv610 failure

May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Initialized drm 1.1.0 20060810
May 12 23:42:05 <kern.crit> moby kernel: drmn0: <Radeon HD 2400 XT> on vgapci0
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] RADEON_IS_PCIE
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] initializing kernel modesetting (RV610 0x1002:0x94C1 0x1028:0x0D02).
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] register mmio base: 0xFE9F0000
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] register mmio size: 65536
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_atrm_get_bios: ===> Try ATRM...
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_atrm_get_bios: pci_find_class() found: 0:1:0:0, vendor=1002, device=94c1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_atrm_get_bios: Get ACPI device handle
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_acpi_vfct_bios: ===> Try VFCT...
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_acpi_vfct_bios: Get "VFCT" ACPI table
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_acpi_vfct_bios: Failed to get "VFCT" table: AE_NOT_FOUND
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] igp_read_bios_from_vram: ===> Try IGP's VRAM...
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] igp_read_bios_from_vram: VRAM base address: 0xd0000000
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] igp_read_bios_from_vram: Map address: 0xfffff800d0000000 (262144 bytes)
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] igp_read_bios_from_vram: Incorrect BIOS signature: 0xFFFF
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_read_bios: ===> Try PCI Expansion ROM...
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_read_bios: Map address: 0xfffff800000c0000 (131072 bytes)
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] ATOM BIOS: 113
May 12 23:42:05 <kern.crit> moby kernel: drmn0: info: VRAM: 256M 0x0000000000000000 - 0x000000000FFFFFFF (256M used)
May 12 23:42:05 <kern.crit> moby kernel: drmn0: info: GTT: 512M 0x0000000010000000 - 0x000000002FFFFFFF
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Detected VRAM RAM=256M, BAR=256M
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] RAM width 64bits DDR
May 12 23:42:05 <kern.crit> moby kernel: [TTM] Zone  kernel: Available graphics memory: 2016864 kiB
May 12 23:42:05 <kern.crit> moby kernel: [TTM] Initializing pool allocator
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon: 256M of VRAM memory ready
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon: 512M of GTT memory ready.
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Driver supports precise vblank timestamp query.
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon: irq initialized.
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] GART: num cpu pages 131072, num gpu pages 131072
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] probing gen 2 caps for device 8086:29b1 = 1/0
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Loading RV610 Microcode
May 12 23:42:05 <kern.crit> moby kernel: firmware: 'radeonkmsfw_RV610_pfp' version 0: 2304 bytes loaded at 0xffffffff81fd60d0
May 12 23:42:05 <kern.crit> moby kernel: firmware: 'radeonkmsfw_RV610_me' version 0: 21504 bytes loaded at 0xffffffff81fd80d0
May 12 23:42:05 <kern.crit> moby kernel: firmware: 'radeonkmsfw_R600_rlc' version 0: 3072 bytes loaded at 0xffffffff81fde0d0
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] PCIE GART of 512M enabled (table at 0x0000000000040000).
May 12 23:42:05 <kern.crit> moby kernel: drmn0: info: WB enabled
May 12 23:42:05 <kern.crit> moby kernel: drmn0: info: fence driver on ring 0 use gpu addr 0x0000000010000c00 and cpu addr 0x0xfffff80076c33c00
May 12 23:42:05 <kern.crit> moby kernel: drmn0: info: fence driver on ring 3 use gpu addr 0x0000000010000c0c and cpu addr 0x0xfffff80076c33c0c
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] ring test on 0 succeeded in 0 usecs
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] ring test on 3 succeeded in 1 usecs
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] ib test on ring 0 succeeded in 0 usecs
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] ib test on ring 3 succeeded in 1 usecs
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon_device_init: Taking over the fictitious range 0xd0000000-0xe0000000
May 12 23:42:05 <kern.crit> moby kernel: iicbus0: <Philips I2C bus> on iicbb0 addr 0xff
May 12 23:42:05 <kern.crit> moby kernel: iic0: <I2C generic I/O> on iicbus0
May 12 23:42:05 <kern.crit> moby kernel: iicbus1: <Philips I2C bus> on iicbb1 addr 0x0
May 12 23:42:05 <kern.crit> moby kernel: iic1: <I2C generic I/O> on iicbus1
May 12 23:42:05 <kern.crit> moby kernel: iicbus2: <Philips I2C bus> on iicbb2 addr 0x0
May 12 23:42:05 <kern.crit> moby kernel: iic2: <I2C generic I/O> on iicbus2
May 12 23:42:05 <kern.crit> moby kernel: iicbus3: <Philips I2C bus> on iicbb3 addr 0x0
May 12 23:42:05 <kern.crit> moby kernel: iic3: <I2C generic I/O> on iicbus3
May 12 23:42:05 <kern.crit> moby kernel: iicbus4: <Philips I2C bus> on iicbb4 addr 0x0
May 12 23:42:05 <kern.crit> moby kernel: iic4: <I2C generic I/O> on iicbus4
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Radeon Display Connectors
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Connector 0:
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   DIN-1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   Encoders:
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]     TV1: INTERNAL_KLDSCP_DAC2
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Connector 1:
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   DVI-I-1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   HPD2
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   DDC: 0x7e50 0x7e50 0x7e54 0x7e54 0x7e58 0x7e58 0x7e5c 0x7e5c
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   Encoders:
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]     CRT2: INTERNAL_KLDSCP_DAC2
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]     DFP1: INTERNAL_KLDSCP_TMDS1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Connector 2:
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   DVI-I-2
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   HPD1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   DDC: 0x7e40 0x7e40 0x7e44 0x7e44 0x7e48 0x7e48 0x7e4c 0x7e4c
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]   Encoders:
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]     CRT1: INTERNAL_KLDSCP_DAC1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm]     DFP2: INTERNAL_LVTM1
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] Internal thermal controller with fan control
May 12 23:42:05 <kern.crit> moby kernel: info: [drm] radeon: power management initialized
May 12 23:42:06 <kern.crit> moby kernel: info: [drm] fb mappable at 0xD0142000
May 12 23:42:06 <kern.crit> moby kernel: info: [drm] vram apper at 0xD0000000
May 12 23:42:06 <kern.crit> moby kernel: info: [drm] size 8294400
May 12 23:42:06 <kern.crit> moby kernel: info: [drm] fb depth is 24
May 12 23:42:06 <kern.crit> moby kernel: info: [drm]    pitch is 6912
May 12 23:42:06 <kern.crit> moby kernel: fbd0 on drmn0
May 12 23:42:06 <kern.crit> moby kernel: VT: Replacing driver "vga" with new "fb".
May 12 23:42:06 <kern.crit> moby kernel: lock order reversal:
May 12 23:42:06 <kern.crit> moby kernel: 1st 0xffffffff81438a08 vtdev (vtdev) @ /usr/src/sys/dev/vt/vt_core.c:2070
May 12 23:42:06 <kern.crit> moby kernel: 2nd 0xfffff80002de1808 ttymtx (ttymtx) @ /usr/src/sys/kern/subr_terminal.c:235
May 12 23:42:06 <kern.crit> moby kernel: KDB: stack backtrace:
May 12 23:42:06 <kern.crit> moby kernel: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe011a161150
May 12 23:42:06 <kern.crit> moby kernel: kdb_backtrace() at
May 12 23:42:06 <kern.crit> moby kernel: kdb_backtrace+0x39/frame 0xfffffe011a161200
May 12 23:42:06 <kern.crit> moby kernel: witness_checkorder() at
May 12 23:42:06 <kern.crit> moby kernel: witness_checkorder+0xdc2/frame 0xfffffe011a161290
May 12 23:42:06 <kern.crit> moby kernel: __mtx_lock_flags() at
May 12 23:42:06 <kern.crit> moby kernel: __mtx_lock_flags+0xa8/frame 0xfffffe011a1612e0
May 12 23:42:06 <kern.crit> moby kernel: terminal_mute() at
May 12 23:42:06 <kern.crit> moby kernel: terminal_mute+0x52/frame 0xfffffe011a161300
May 12 23:42:06 <kern.crit> moby kernel: vt_allocate() at
May 12 23:42:06 <kern.crit> moby kernel: vt_allocate+0x113/frame 0xfffffe011a161360
May 12 23:42:06 <kern.crit> moby kernel: vt_fb_attach() at vt_fb_attach+0x16/frame 0xfffffe011a161370
May 12 23:42:06 <kern.crit> moby kernel: fbd_register() at
May 12 23:42:06 <kern.crit> moby kernel: fbd_register+0x19d/frame 0xfffffe011a1613b0
May 12 23:42:06 <kern.crit> moby kernel: device_attach() at
May 12 23:42:06 <kern.crit> moby kernel: device_attach+0x3a5/frame 0xfffffe011a161410
May 12 23:42:06 <kern.crit> moby kernel: drm_fb_helper_single_fb_probe() at drm_fb_helper_single_fb_probe+0x2b6/frame 0xfffffe011a161460
May 12 23:42:06 <kern.crit> moby kernel: drm_fb_helper_initial_config() at drm_fb_helper_initial_config+0xc4/frame 0xfffffe011a1614a0
May 12 23:42:06 <kern.crit> moby kernel: radeon_fbdev_init() at
May 12 23:42:06 <kern.crit> moby kernel: radeon_fbdev_init+0xb9/frame 0xfffffe011a1614d0
May 12 23:42:06 <kern.crit> moby kernel: radeon_modeset_init() at
May 12 23:42:06 <kern.crit> moby kernel: radeon_modeset_init+0x95a/frame 0xfffffe011a161540
May 12 23:42:06 <kern.crit> moby kernel: radeon_driver_load_kms() at radeon_driver_load_kms+0xc9/frame 0xfffffe011a161580
May 12 23:42:06 <kern.crit> moby kernel: drm_attach() at
May 12 23:42:06 <kern.crit> moby kernel: drm_attach+0x935/frame 0xfffffe011a161610
May 12 23:42:06 <kern.crit> moby kernel: device_attach() at device_attach+0x3a5/frame 0xfffffe011a161670