A tela fica repetidamente preta por alguns segundos após a suspensão

Question

Quando eu suspendo meu laptop e retomo, a tela fica preta repetidamente por alguns segundos e depois volta ao normal. Isso acontece aleatoriamente, cerca de uma vez por minuto, sem que o meu comportamento tenha qualquer influência perceptível sobre ele.

Especificações gerais

• CPU : CPU Intel (R) Core (TM) i7-4750HQ @ 2.00GHz
• Chip gráfico : Iris Pro Graphics 5200
• Versão do Ubuntu : 14.10 (mas isso aconteceu em versões anteriores e também no Linux Mint)

saída dmesg

Curiosamente, o dmesg é inundado com muitas cópias da seguinte mensagem:

[29409.601998] ------------[ cut here ]------------
[29409.602011] WARNING: CPU: 2 PID: 14850 at /build/buildd/linux-3.16.0/drivers/gpu/drm/i915/intel_display.c:7260 hsw_enable_pc8+0x50a/0x640 [i915]()
[29409.602012] WRPLL1 enabled
[29409.602013] Modules linked in: ctr ccm snd_usb_audio snd_usbmidi_lib hid_cherry hid_generic uvcvideo videobuf2_vmalloc videobuf2_memops usbhid videobuf2_core v4l2_common hid videodev media btusb snd_hda_codec_via snd_hda_codec_generic snd_hda_codec_hdmi joydev bnep rfcomm bluetooth arc4 6lowpan_iphc x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel binfmt_misc iwlmvm snd_hda_intel aesni_intel snd_hda_controller mac80211 snd_hda_codec aes_x86_64 snd_hwdep lrw snd_pcm gf128mul snd_seq_midi glue_helper snd_seq_midi_event iwlwifi ablk_helper cryptd serio_raw snd_rawmidi snd_seq cfg80211 snd_seq_device snd_timer rtsx_pci_ms memstick lpc_ich parport_pc snd i915 shpchp wmi drm_kms_helper ppdev drm mei_me lp mei video soundcore tpm_infineon i2c_algo_bit
[29409.602042]  mac_hid parport rtsx_pci_sdmmc e1000e ahci psmouse libahci rtsx_pci ptp pps_core
[29409.602047] CPU: 2 PID: 14850 Comm: kworker/2:1 Tainted: G        W     3.16.0-28-generic #37-Ubuntu
[29409.602048] Hardware name: Notebook                         W740SU                          /W740SU                          , BIOS 4.6.5 10/02/2013
[29409.602050] Workqueue: pm pm_runtime_work
[29409.602051]  0000000000000009 ffff8803ed7dfc08 ffffffff81781e6a ffff8803ed7dfc50
[29409.602053]  ffff8803ed7dfc40 ffffffff8106fedd ffff8800d70a0000 ffff8804087ff368
[29409.602055]  ffff8804087ff370 ffff880409231098 0000000000000008 ffff8803ed7dfca0
[29409.602057] Call Trace:
[29409.602060]  [<ffffffff81781e6a>] dump_stack+0x45/0x56
[29409.602063]  [<ffffffff8106fedd>] warn_slowpath_common+0x7d/0xa0
[29409.602065]  [<ffffffff8106ff4c>] warn_slowpath_fmt+0x4c/0x50
[29409.602080]  [<ffffffffc043af2a>] hsw_enable_pc8+0x50a/0x640 [i915]
[29409.602089]  [<ffffffffc03e29ad>] intel_runtime_suspend+0x1ad/0x8d0 [i915]
[29409.602092]  [<ffffffff813e4f50>] ? pci_legacy_suspend_late+0xf0/0xf0
[29409.602095]  [<ffffffff813e4faf>] pci_pm_runtime_suspend+0x5f/0x150
[29409.602098]  [<ffffffff813e4f50>] ? pci_legacy_suspend_late+0xf0/0xf0
[29409.602100]  [<ffffffff814da4e2>] __rpm_callback+0x32/0xe0
[29409.602101]  [<ffffffff814da5b6>] rpm_callback+0x26/0xa0
[29409.602103]  [<ffffffff814db06c>] rpm_suspend+0x10c/0x670
[29409.602106]  [<ffffffff8107e3e8>] ? add_timer+0x18/0x30
[29409.602108]  [<ffffffff8108b4fb>] ? __queue_delayed_work+0x8b/0x1c0
[29409.602110]  [<ffffffff814dc2e2>] pm_runtime_work+0xd2/0x130
[29409.602113]  [<ffffffff8108da32>] process_one_work+0x182/0x4e0
[29409.602115]  [<ffffffff8108ddfb>] worker_thread+0x6b/0x6a0
[29409.602117]  [<ffffffff81784aed>] ? __schedule+0x39d/0x890
[29409.602119]  [<ffffffff8108dd90>] ? process_one_work+0x4e0/0x4e0
[29409.602122]  [<ffffffff81094c6b>] kthread+0xdb/0x100
[29409.602125]  [<ffffffff81094b90>] ? kthread_create_on_node+0x1c0/0x1c0
[29409.602127]  [<ffffffff81789dfc>] ret_from_fork+0x7c/0xb0
[29409.602130]  [<ffffffff81094b90>] ? kthread_create_on_node+0x1c0/0x1c0
[29409.602132] ---[ end trace c6db507515da1c2c ]---
[29411.594033] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off

Outras informações potencialmente úteis

> uname -a
Linux holly 3.16.0-28-generic #37-Ubuntu SMP Mon Dec 8 17:15:28 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

> glxinfo
[…]
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile 
OpenGL core profile version string: 3.3 (Core Profile) Mesa 10.3.0
[…]

> lspci
00:00.0 Host bridge: Intel Corporation Crystal Well DRAM Controller (rev 08)
00:02.0 VGA compatible controller: Intel Corporation Crystal Well Integrated Graphics Controller (rev 08)
00:03.0 Audio device: Intel Corporation Crystal Well HD Audio Controller (rev 08)
00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-V (rev 05)
00:1a.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5)
00:1c.1 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #2 (rev d5)
00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d5)
00:1d.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation HM87 Express LPC Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 8 Series/C220 Series Chipset Family 6-port SATA Controller 1 [AHCI mode] (rev 05)
00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05)
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5229 PCI Express Card Reader (rev 01)
03:00.0 Network controller: Intel Corporation Wireless 7260 (rev 73)

> lsusb
Bus 002 Device 002: ID 8087:8000 Intel Corp. 
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:8008 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 004: ID 8087:07dc Intel Corp. 
Bus 003 Device 009: ID 045e:070f Microsoft Corp. 
Bus 003 Device 008: ID 046a:0023 Cherry GmbH CyMotion Master Linux Keyboard G230
Bus 003 Device 005: ID 5986:0536 Acer, Inc 
Bus 003 Device 007: ID 046d:c03e Logitech, Inc. Premium Optical Wheel Mouse (M-BT58)
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

    

Answer 1

Meu palpite pessoal é que o problema não está nas configurações nem no Ubuntu, mas no próprio monitor. Eu experimentei um monte de monitores diferentes e concluí que alguns fabricantes preferem não nos dar a opção de simplesmente fechar os olhos para desligar as chavetas de tela irritantes que podem ocorrer durante esses períodos de transição e, em vez disso, deixar o monitor vazio por vários segundos. É possível que este apagamento de tela seja uma opção nas configurações do monitor.

Editar: estou estendendo minha conclusão anterior para estender para o hardware gráfico do laptop, seja considerado o monitor ou não. Eu não acho que o problema possa ser resolvido através de software ou drivers.