These messages also frequently appear in dmesg:
[10685.248773] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
[10685.249135] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
[10685.259859] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
[10685.260221] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
This is dubious, but the reason I was paying attention is Xorg (at least the display) getting into a weird locked up state (screen not updating until I restart X) when switching video modes (I think), specifically when Steam (the game thingy) in "big picture mode" tries to run a game. But this could also very well just be Steam doing something wrong (it's a new system so I'm not sure where the fault might lie).
Also happening on:
Linux pebble 4.2.0-18-generic #22-Ubuntu SMP Fri Nov 6 18:25:50 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
$ dmidecode -s bios-version 86A.0348. 2015.0703. 1124
RYBDWi35.
Release notes for 0350 BIOS don't mention anything regarding graphics changes, just a fix for some audio bug.
$ lspci -s 00:02.0 -v
Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [a4] PCI Advanced Features
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09) (prog-if 00 [VGA controller])
Subsystem: Intel Corporation Device 2057
Flags: bus master, fast devsel, latency 0, IRQ 45
Memory at a9000000 (64-bit, non-prefetchable) [size=16M]
Memory at b0000000 (64-bit, prefetchable) [size=256M]
I/O ports at 3000 [size=64]
Expansion ROM at <unassigned> [disabled]
Kernel driver in use: i915
[10685.158305] WARNING: CPU: 2 PID: 797 at /build/ linux-jJX2Dm/ linux-4. 2.0/drivers/ gpu/drm/ i915/intel_ display. c:1365 assert_ plane.constprop .98+0x6f/ 0x90 [i915]() temp_thermal intel_powerclamp snd_compress coretemp ac97_bus snd_pcm_dmaengine kvm_intel snd_seq_midi kvm snd_seq_midi_event iwlmvm crct10dif_pclmul crc32_pclmul mac80211 snd_rawmidi ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd snd_seq iwlwifi snd_hda_ codec_realtek snd_hda_codec_hdmi snd_seq_device snd_hda_ codec_generic snd_hda_intel serio_raw snd_hda_codec cfg80211 snd_hda_core snd_hwdep snd_pcm mei_me shpchp snd_timer lpc_ich ir_lirc_codec ir_xmp_decoder lirc_dev ir_mce_kbd_decoder ir_sharp_decoder ir_sanyo_decoder ir_sony_decoder mei platform i2c_designware_core acpi_als spi_pxa2xx_platform mac_hid kfifo_buf industrialio parport_pc ppdev lp parport autofs4 i915 e1000e i2c_algo_bit psmouse ptp drm_kms_helper ahci drm libahci pps_core video i2c_hid hid sdhci_acpi sdhci 86A.0348. 2015.0703. 1124 07/03/2015 c09>] dump_stack+ 0x45/0x57 3c6>] warn_slowpath_ common+ 0x86/0xc0 455>] warn_slowpath_ fmt+0x55/ 0x70 14f>] assert_ plane.constprop .98+0x6f/ 0x90 [i915] d59>] hsw_disable_ ips+0x39/ 0x180 [i915] ef4>] intel_pre_ disable_ primary+ 0x54/0x90 [i915] f6a>] intel_crtc_ disable_ planes+ 0x3a/0x100 [i915] 8c6>] __intel_ set_mode+ 0x226/0xb60 [i915] d16>] intel_crtc_ set_config+ 0x2b6/0x580 [i915] 4c6>] drm_mode_ set_config_ internal+ 0x66/0x100 [drm] 632>] restore_ fbdev_mode+ 0xc2/0xf0 [drm_kms_helper] 4e9>] drm_fb_ helper_ restore_ fbdev_mode_ unlocked+ 0x29/0x70 [drm_kms_helper] 552>] drm_fb_ helper_ set_par+ 0x22/0x40 [drm_kms_helper] 3ba>] intel_fbdev_ set_par+ 0x1a/0x60 [i915] d02>] ? ext4_mark_ iloc_dirty+ 0x462/0x710 f16>] fb_set_ var+0x236/ 0x460 0cf>] ? jbd2_journal_ dirty_metadata+ 0xbf/0x240 d08>] ? __ext4_ handle_ dirty_metadata+ 0x48/0x1f0 2c3>] ? __find_ get_block+ 0xd3/0x100 1a2>] fbcon_blank+ 0x312/0x360 0cf>] ? jbd2_journal_ dirty_metadata+ 0xbf/0x240 9f3>] do_unblank_ screen+ 0xd3/0x1a0 eda>] vt_ioctl+ 0x50a/0x12f0 916>] ? __slab_ free+0xb6/ 0x2c0 19c>] tty_ioctl+ 0x3cc/0xbb0 481>] ? kzfree+0x31/0x40 e96>] ? kfree+0x126/0x130 8a5>] do_vfs_ ioctl+0x295/ 0x480 7a4>] ? mntput+0x24/0x40 f30>] ? __fput+0x190/0x220 b09>] SyS_ioctl+0x79/0x90 9f2>] entry_SYSCALL_ 64_fastpath+ 0x16/0x75
[10685.158306] plane A assertion failure (expected on, current off)
[10685.158340] Modules linked in: drbg ansi_cprng ctr ccm rfcomm bnep input_leds nls_iso8859_1 btusb btrtl btbcm btintel hid_generic bluetooth usbhid arc4 snd_soc_rt5640 snd_soc_rl6231 intel_rapl snd_soc_core iosf_mbi x86_pkg_
[10685.158360] ir_jvc_decoder ir_rc6_decoder ir_rc5_decoder ir_nec_decoder snd soundcore rc_rc6_mce snd_soc_sst_acpi nuvoton_cir dw_dmac rc_core dw_dmac_core 8250_dw acpi_pad i2c_designware_
[10685.158363] CPU: 2 PID: 797 Comm: Xorg Not tainted 4.2.0-18-generic #22-Ubuntu
[10685.158363] Hardware name: /NUC5i5RYB, BIOS RYBDWi35.
[10685.158367] 0000000000000000 000000004010fe72 ffff88024b2fb718 ffffffff817e8c09
[10685.158369] 0000000000000000 ffff88024b2fb770 ffff88024b2fb758 ffffffff8107b3c6
[10685.158370] 0000000000000000 0000000000000000 ffff880248340000 ffff88024cf63000
[10685.158371] Call Trace:
[10685.158376] [<ffffffff817e8
[10685.158379] [<ffffffff8107b
[10685.158381] [<ffffffff8107b
[10685.158398] [<ffffffffc0215
[10685.158414] [<ffffffffc021e
[10685.158428] [<ffffffffc021e
[10685.158442] [<ffffffffc021e
[10685.158456] [<ffffffffc021f
[10685.158471] [<ffffffffc0226
[10685.158485] [<ffffffffc0096
[10685.158491] [<ffffffffc010c
[10685.158497] [<ffffffffc010e
[10685.158501] [<ffffffffc010e
[10685.158517] [<ffffffffc0234
[10685.158521] [<ffffffff81287
[10685.158524] [<ffffffff81447
[10685.158527] [<ffffffff812d4
[10685.158530] [<ffffffff812b7
[10685.158533] [<ffffffff81233
[10685.158536] [<ffffffff8143e
[10685.158538] [<ffffffff812d4
[10685.158541] [<ffffffff814d3
[10685.158543] [<ffffffff814c8
[10685.158545] [<ffffffff811dd
[10685.158548] [<ffffffff814bc
[10685.158551] [<ffffffff811a7
[10685.158552] [<ffffffff811dd
[10685.158555] [<ffffffff81210
[10685.158557] [<ffffffff8121d
[10685.158559] [<ffffffff811fe
[10685.158562] [<ffffffff81210
[10685.158564] [<ffffffff817ef
[10685.158566] ---[ end trace 628f0dd29de1b3e9 ]---
These messages also frequently appear in dmesg: irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)! irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)! irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)! irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
[10685.248773] [drm:gen8_
[10685.249135] [drm:gen8_
[10685.259859] [drm:gen8_
[10685.260221] [drm:gen8_
This is dubious, but the reason I was paying attention is Xorg (at least the display) getting into a weird locked up state (screen not updating until I restart X) when switching video modes (I think), specifically when Steam (the game thingy) in "big picture mode" tries to run a game. But this could also very well just be Steam doing something wrong (it's a new system so I'm not sure where the fault might lie).