A tela permanece preta após a suspensão

Question

A suspensão costumava funcionar bem no meu laptop, mas desde uma atualização recente estou com um problema. Depois que eu acordo o laptop da suspensão, a tela não liga. Tudo o mais parece ligado, mas sem imagem na tela. O laptop está totalmente desperto, mas não há imagem na tela. No entanto, há uma "correção" que encontrei. Se eu acordei o laptop e estou de frente para a tela preta, posso usar um cabo HDMI para ativá-lo. O que tenho que fazer é conectar um cabo HDMI (um que esteja conectado a uma TV, por exemplo), e apenas o ato de ligá-lo irá "acordar" a tela. É muito estranho, mas funciona. O problema, é claro, é que eu não posso levar uma tv por aí aonde eu for, então essa não é uma solução permanente.

Aqui está mais um código de depuração.

Entradas de diário típicas ao acordar da suspensão:

Apr 19 18:55:08 george kernel: PM: Syncing filesystems ... done.
Apr 19 18:55:08 george kernel: Freezing user space processes ... (elapsed 0.001 seconds) done.
Apr 19 18:55:08 george kernel: OOM killer disabled.
Apr 19 18:55:08 george kernel: Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
Apr 19 18:55:08 george kernel: Suspending console(s) (use no_console_suspend to debug)
Apr 19 18:55:08 george kernel: wlp1s0: deauthenticating from 51:b7:bf:0a:bc:63 by local choice (Reason: 3=DEAUTH_LEAVING)
Apr 19 18:55:08 george kernel: sd 0:0:0:0: [sda] Synchronizing SCSI cache
Apr 19 18:55:08 george kernel: sd 0:0:0:0: [sda] Stopping disk
Apr 19 18:55:08 george kernel: wlp1s0: failed to remove key (1, ff:ff:ff:ff:ff:ff) from hardware (-22)
Apr 19 18:55:08 george kernel: ACPI: Preparing to enter system sleep state S3
Apr 19 18:55:08 george kernel: ACPI: EC: event blocked
Apr 19 18:55:08 george kernel: ACPI: EC: EC stopped
Apr 19 18:55:08 george kernel: PM: Saving platform NVS memory
Apr 19 18:55:08 george kernel: Disabling non-boot CPUs ...
Apr 19 18:55:08 george kernel: smpboot: CPU 1 is now offline
Apr 19 18:55:08 george kernel: ACPI: Low-level resume complete
Apr 19 18:55:08 george kernel: ACPI: EC: EC started
Apr 19 18:55:08 george kernel: PM: Restoring platform NVS memory
Apr 19 18:55:08 george kernel: Enabling non-boot CPUs ...
Apr 19 18:55:08 george kernel: x86: Booting SMP configuration:
Apr 19 18:55:08 george kernel: smpboot: Booting Node 0 Processor 1 APIC 0x2
Apr 19 18:55:08 george kernel:  cache: parent cpu1 should not be sleeping
Apr 19 18:55:08 george kernel: CPU1 is up
Apr 19 18:55:08 george kernel: ACPI: Waking up from system sleep state S3
Apr 19 18:55:08 george kernel: ACPI: EC: event unblocked
Apr 19 18:55:08 george kernel: [drm:intel_display_resume [i915]] *ERROR* Restoring old state failed with -22
Apr 19 18:55:08 george kernel: sd 0:0:0:0: [sda] Starting disk
Apr 19 18:55:08 george kernel: usb 1-7: reset high-speed USB device number 5 using xhci_hcd
Apr 19 18:55:08 george kernel: ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
Apr 19 18:55:08 george kernel: ata1.00: configured for UDMA/133
Apr 19 18:55:08 george kernel: usb 1-3: reset high-speed USB device number 2 using xhci_hcd
Apr 19 18:55:08 george kernel: OOM killer enabled.
Apr 19 18:55:08 george systemd-logind[266]: Lid opened.
Apr 19 18:55:08 george dhcpcd[14830]: wlp1s0: carrier lost
Apr 19 18:55:08 george kernel: Restarting tasks ... done.
Apr 19 18:55:08 george kernel: PM: suspend exit
Apr 19 18:55:08 george systemd-sleep[25353]: System resumed.
Apr 19 18:55:08 george systemd[1]: Started Suspend.
Apr 19 18:55:08 george systemd[1]: sleep.target: Unit not needed anymore. Stopping.
Apr 19 18:55:08 george systemd[1]: Stopped target Sleep.
Apr 19 18:55:08 george systemd[1]: Reached target Suspend.
Apr 19 18:55:08 george systemd[1]: suspend.target: Unit not needed anymore. Stopping.
Apr 19 18:55:08 george systemd[1]: Stopped target Suspend.
Apr 19 18:55:08 george systemd-logind[266]: Operation 'sleep' finished.
Apr 19 18:55:08 george wicd[271]: sending signal ALRM to pid 14830
Apr 19 18:55:08 george wicd[271]: waiting for pid 14830 to exit
Apr 19 18:55:08 george dhcpcd[25410]: sending signal ALRM to pid 14830
Apr 19 18:55:08 george dhcpcd[25410]: waiting for pid 14830 to exit
Apr 19 18:55:08 george dhcpcd[14830]: wlp1s0: deleting route to 192.168.178.0/24
Apr 19 18:55:08 george dhcpcd[14830]: wlp1s0: deleting default route via 192.168.178.1
Apr 19 18:55:08 george dhcpcd[14830]: received SIGALRM, releasing
Apr 19 18:55:08 george dhcpcd[14830]: wlp1s0: removing interface
Apr 19 18:55:08 george dhcpcd[14830]: dhcpcd exited
Apr 19 18:55:08 george kernel: IPv6: ADDRCONF(NETDEV_UP): wlp1s0: link is not ready

E aqui detalhes do cartão VGA:

$ lspci -vnn | grep VGA -A 12
00:02.0 VGA compatible controller [0300]: Intel Corporation HD Graphics [8086:1606] (rev 08) (prog-if 00 [VGA controller])
    Subsystem: Intel Corporation HD Graphics [8086:1606]
    Flags: bus master, fast devsel, latency 0, IRQ 46
    Memory at e0000000 (64-bit, non-prefetchable) [size=16M]
    Memory at d0000000 (64-bit, prefetchable) [size=256M]
    I/O ports at 1800 [size=64]
    [virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
    Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
    Capabilities: [d0] Power Management version 2
    Capabilities: [a4] PCI Advanced Features
    Kernel driver in use: i915
    Kernel modules: i915

Eu usei o kernel mais recente antes, mas mudei para o LTS depois que este problema surgiu:

$ uname -a Linux george 4.14.34-1-lts #1 SMP Thu Apr 12 20:30:09 CEST 2018 x86_64 GNU/Linux

Existe alguém que tenha uma ideia do que isso possa ser?

Estou usando o i3 como gerenciador de janelas, sem ambiente de desktop e sistema operacional Arch Linux.