Built-in screen flicker on ThinkPad Carbon X1 9th Gen when external display connected on certain resolutions

I have an issue with screen flicker identical to this effect described here: Regular screen glitch on Thinkpad T14s Gen3 AMD but there is no AMD graphics for which to try the suggested fix. I have repeated the issue with different external HDMI displays and on both Wayland and X11. This issue only occurs when the external display is connected (1920x1080 tested) when the internal resolution is e.g. 1680x1050, but not when 1920x1200. The laptop is still under warranty, and was purchased to use with Fedora only (I believe it is certified as such?).

Is this a hardware issue, or is a software/config change fix possible/available?

lshw output for display and system are below:

 computer                    
    description: Notebook
    product: 20XXSEDW00 (LENOVO_MT_20XX_BU_Think_FM_ThinkPad X1 Carbon Gen 9)
    vendor: LENOVO
    version: ThinkPad X1 Carbon Gen 9
    serial: [REMOVED]
    width: 64 bits
    capabilities: smbios-3.2.0 dmi-3.2.0 smp vsyscall32
    configuration: administrator_password=disabled chassis=notebook family=ThinkPad X1 Carbon Gen 9 power-on_password=disabled sku=LENOVO_MT_20XX_BU_Think_FM_ThinkPad X1 Carbon Gen 9 uuid=[REMOVED]
  *-display
       description: VGA compatible controller
       product: TigerLake-LP GT2 [Iris Xe Graphics]
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       logical name: /dev/fb0
       version: 01
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
       configuration: depth=32 driver=i915 latency=0 mode=1920x1200 visual=truecolor xres=1920 yres=1200
       resources: iomemory:600-5ff iomemory:400-3ff irq:138 memory:603c000000-603cffffff memory:4000000000-401fffffff ioport:3000(size=64) memory:c0000-dffff memory:4100000000-4106ffffff memory:4020000000-40ffffffffcomputer                    
1 Like

Please post the output of inxi -Fzxx so we can see everything. Also please use the Preformatted text tags </> on the tool bar to retain formatting and not the block quote tags. (I edited your post above to show that formatting)

Your post appears to show the exact same data for display twice and only an intel GPU.

Sure, many thanks for taking a look. here is the output of inxi -Fzxx:

System:
  Kernel: 6.2.9-200.fc37.x86_64 arch: x86_64 bits: 64 compiler: gcc
    v: 2.38-25.fc37 Desktop: GNOME v: 43.4 tk: GTK v: 3.24.37 wm: gnome-shell
    dm: GDM Distro: Fedora release 37 (Thirty Seven)
Machine:
  Type: Laptop System: LENOVO product: 20XXSEDW00 v: ThinkPad X1 Carbon Gen 9
    serial: <superuser required> Chassis: type: 10 serial: <superuser required>
  Mobo: LENOVO model: 20XXSEDW00 serial: <superuser required> UEFI: LENOVO
    v: N32ET83W (1.59 ) date: 02/09/2023
Battery:
  ID-1: BAT0 charge: 57.6 Wh (100.0%) condition: 57.6/57.0 Wh (101.0%)
    volts: 17.2 min: 15.4 model: Sunwoda 5B10W13975 serial: <filter>
    status: full
CPU:
  Info: quad core model: 11th Gen Intel Core i7-1165G7 bits: 64 type: MT MCP
    arch: Tiger Lake rev: 1 cache: L1: 320 KiB L2: 5 MiB L3: 12 MiB
  Speed (MHz): avg: 2104 high: 2800 min/max: 400/4700 cores: 1: 2800 2: 970
    3: 1084 4: 2800 5: 2800 6: 2800 7: 782 8: 2800 bogomips: 44851
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel TigerLake-LP GT2 [Iris Xe Graphics] vendor: Lenovo
    driver: i915 v: kernel arch: Gen-12.1 ports: active: HDMI-A-1,eDP-1
    empty: DP-1, DP-2, DP-3, DP-4, HDMI-A-2, HDMI-A-3 bus-ID: 00:02.0
    chip-ID: 8086:9a49
  Device-2: IMC Networks Integrated Camera type: USB driver: uvcvideo
    bus-ID: 3-4:3 chip-ID: 13d3:5411
  Display: x11 server: X.Org v: 1.20.14 with: Xwayland v: 22.1.9
    compositor: gnome-shell driver: X: loaded: modesetting unloaded: fbdev,vesa
    dri: iris gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 3840x1200 s-dpi: 96
  Monitor-1: HDMI-A-1 mapped: HDMI-1 pos: left model: Idek Iiyama PLX2783H
    res: 1920x1080 dpi: 82 diag: 686mm (27")
  Monitor-2: eDP-1 pos: primary,right model: ChiMei InnoLux 0x1417
    res: 1920x1200 dpi: 162 diag: 355mm (14")
  API: OpenGL v: 4.6 Mesa 22.3.7 renderer: Mesa Intel Xe Graphics (TGL GT2)
    direct-render: Yes
Audio:
  Device-1: Intel Tiger Lake-LP Smart Sound Audio vendor: Lenovo
    driver: sof-audio-pci-intel-tgl bus-ID: 00:1f.3 chip-ID: 8086:a0c8
  Sound API: ALSA v: k6.2.9-200.fc37.x86_64 running: yes
  Sound Server-1: PulseAudio v: 16.1 running: no
  Sound Server-2: PipeWire v: 0.3.68 running: yes
Network:
  Device-1: Intel Wi-Fi 6 AX201 driver: iwlwifi v: kernel bus-ID: 00:14.3
    chip-ID: 8086:a0f0
  IF: wlp0s20f3 state: up mac: <filter>
  Device-2: Lenovo USB-C to LAN type: USB driver: r8152 bus-ID: 2-2:2
    chip-ID: 17ef:720c
  IF: enp0s13f0u2 state: up speed: 1000 Mbps duplex: full mac: <filter>
  Device-3: ASIX AX88179 Gigabit Ethernet type: USB driver: ax88179_178a
    bus-ID: 4-1.4:3 chip-ID: 0b95:1790
  IF: enp0s20f0u1u4 state: down mac: <filter>
  IF-ID-1: tun0 state: unknown speed: 10000 Mbps duplex: full mac: N/A
Bluetooth:
  Device-1: Intel AX201 Bluetooth type: USB driver: btusb v: 0.8
    bus-ID: 3-10:5 chip-ID: 8087:0026
  Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends
Drives:
  Local Storage: total: 953.87 GiB used: 115.59 GiB (12.1%)
  ID-1: /dev/nvme0n1 vendor: Micron model: MTFDKBA1T0TFH size: 953.87 GiB
    speed: 63.2 Gb/s lanes: 4 serial: <filter> temp: 25.9 C
Partition:
  ID-1: / size: 952.27 GiB used: 115.29 GiB (12.1%) fs: btrfs dev: /dev/dm-0
    mapped: luks-958217d9-6291-44c0-b7d3-3d558c5baf16
  ID-2: /boot size: 973.4 MiB used: 280 MiB (28.8%) fs: ext4
    dev: /dev/nvme0n1p2
  ID-3: /boot/efi size: 598.8 MiB used: 34.9 MiB (5.8%) fs: vfat
    dev: /dev/nvme0n1p1
  ID-4: /home size: 952.27 GiB used: 115.29 GiB (12.1%) fs: btrfs
    dev: /dev/dm-0 mapped: luks-958217d9-6291-44c0-b7d3-3d558c5baf16
Swap:
  ID-1: swap-1 type: zram size: 8 GiB used: 0 KiB (0.0%) priority: 100
    dev: /dev/zram0
Sensors:
  Src: /sys System Temperatures: cpu: 45.0 C mobo: N/A
  Fan Speeds (RPM): N/A
  Power: 12v: N/A 5v: 5 3.3v: N/A vbat: N/A
Info:
  Processes: 583 Uptime: 5h 17m Memory: 31.06 GiB used: 6.6 GiB (21.3%)
  Init: systemd v: 251 target: graphical (5) default: graphical Compilers:
  gcc: 12.2.1 Packages: pm: rpm pkgs: N/A note: see --rpm pm: flatpak pkgs: 1System:
  Kernel: 6.2.9-200.fc37.x86_64 arch: x86_64 bits: 64 compiler: gcc
    v: 2.38-25.fc37 Desktop: GNOME v: 43.4 tk: GTK v: 3.24.37 wm: gnome-shell
    dm: GDM Distro: Fedora release 37 (Thirty Seven)
Machine:
  Type: Laptop System: LENOVO product: 20XXSEDW00 v: ThinkPad X1 Carbon Gen 9
    serial: <superuser required> Chassis: type: 10 serial: <superuser required>
  Mobo: LENOVO model: 20XXSEDW00 serial: <superuser required> UEFI: LENOVO
    v: N32ET83W (1.59 ) date: 02/09/2023
Battery:
  ID-1: BAT0 charge: 57.6 Wh (100.0%) condition: 57.6/57.0 Wh (101.0%)
    volts: 17.2 min: 15.4 model: Sunwoda 5B10W13975 serial: <filter>
    status: full
CPU:
  Info: quad core model: 11th Gen Intel Core i7-1165G7 bits: 64 type: MT MCP
    arch: Tiger Lake rev: 1 cache: L1: 320 KiB L2: 5 MiB L3: 12 MiB
  Speed (MHz): avg: 2104 high: 2800 min/max: 400/4700 cores: 1: 2800 2: 970
    3: 1084 4: 2800 5: 2800 6: 2800 7: 782 8: 2800 bogomips: 44851
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel TigerLake-LP GT2 [Iris Xe Graphics] vendor: Lenovo
    driver: i915 v: kernel arch: Gen-12.1 ports: active: HDMI-A-1,eDP-1
    empty: DP-1, DP-2, DP-3, DP-4, HDMI-A-2, HDMI-A-3 bus-ID: 00:02.0
    chip-ID: 8086:9a49
  Device-2: IMC Networks Integrated Camera type: USB driver: uvcvideo
    bus-ID: 3-4:3 chip-ID: 13d3:5411
  Display: x11 server: X.Org v: 1.20.14 with: Xwayland v: 22.1.9
    compositor: gnome-shell driver: X: loaded: modesetting unloaded: fbdev,vesa
    dri: iris gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 3840x1200 s-dpi: 96
  Monitor-1: HDMI-A-1 mapped: HDMI-1 pos: left model: Idek Iiyama PLX2783H
    res: 1920x1080 dpi: 82 diag: 686mm (27")
  Monitor-2: eDP-1 pos: primary,right model: ChiMei InnoLux 0x1417
    res: 1920x1200 dpi: 162 diag: 355mm (14")
  API: OpenGL v: 4.6 Mesa 22.3.7 renderer: Mesa Intel Xe Graphics (TGL GT2)
    direct-render: Yes
Audio:
  Device-1: Intel Tiger Lake-LP Smart Sound Audio vendor: Lenovo
    driver: sof-audio-pci-intel-tgl bus-ID: 00:1f.3 chip-ID: 8086:a0c8
  Sound API: ALSA v: k6.2.9-200.fc37.x86_64 running: yes
  Sound Server-1: PulseAudio v: 16.1 running: no
  Sound Server-2: PipeWire v: 0.3.68 running: yes
Network:
  Device-1: Intel Wi-Fi 6 AX201 driver: iwlwifi v: kernel bus-ID: 00:14.3
    chip-ID: 8086:a0f0
  IF: wlp0s20f3 state: up mac: <filter>
  Device-2: Lenovo USB-C to LAN type: USB driver: r8152 bus-ID: 2-2:2
    chip-ID: 17ef:720c
  IF: enp0s13f0u2 state: up speed: 1000 Mbps duplex: full mac: <filter>
  Device-3: ASIX AX88179 Gigabit Ethernet type: USB driver: ax88179_178a
    bus-ID: 4-1.4:3 chip-ID: 0b95:1790
  IF: enp0s20f0u1u4 state: down mac: <filter>
  IF-ID-1: tun0 state: unknown speed: 10000 Mbps duplex: full mac: N/A
Bluetooth:
  Device-1: Intel AX201 Bluetooth type: USB driver: btusb v: 0.8
    bus-ID: 3-10:5 chip-ID: 8087:0026
  Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends
Drives:
  Local Storage: total: 953.87 GiB used: 115.59 GiB (12.1%)
  ID-1: /dev/nvme0n1 vendor: Micron model: MTFDKBA1T0TFH size: 953.87 GiB
    speed: 63.2 Gb/s lanes: 4 serial: <filter> temp: 25.9 C
Partition:
  ID-1: / size: 952.27 GiB used: 115.29 GiB (12.1%) fs: btrfs dev: /dev/dm-0
    mapped: luks-958217d9-6291-44c0-b7d3-3d558c5baf16
  ID-2: /boot size: 973.4 MiB used: 280 MiB (28.8%) fs: ext4
    dev: /dev/nvme0n1p2
  ID-3: /boot/efi size: 598.8 MiB used: 34.9 MiB (5.8%) fs: vfat
    dev: /dev/nvme0n1p1
  ID-4: /home size: 952.27 GiB used: 115.29 GiB (12.1%) fs: btrfs
    dev: /dev/dm-0 mapped: luks-958217d9-6291-44c0-b7d3-3d558c5baf16
Swap:
  ID-1: swap-1 type: zram size: 8 GiB used: 0 KiB (0.0%) priority: 100
    dev: /dev/zram0
Sensors:
  Src: /sys System Temperatures: cpu: 45.0 C mobo: N/A
  Fan Speeds (RPM): N/A
  Power: 12v: N/A 5v: 5 3.3v: N/A vbat: N/A
Info:
  Processes: 583 Uptime: 5h 17m Memory: 31.06 GiB used: 6.6 GiB (21.3%)
  Init: systemd v: 251 target: graphical (5) default: graphical Compilers:
  gcc: 12.2.1 Packages: pm: rpm pkgs: N/A note: see --rpm pm: flatpak pkgs: 1
  Shell: Bash v: 5.2.15 running-in: gnome-terminal inxi: 3.3.25

According to that you only have the intel GPU so no other driver could be used. You have the i915 driver installed and in use.

If the screen is flickering that seems to indicate the resolution you are trying to use is not proper for the GPU + Display combination and you probably should switch to a resolution where the flickering does not occur. It should also be possible to set the resolution individually for each monitor.

Thanks for the response. Yes, this is the i915 GPU driver, so the AMD specific fix mentioned in the original post would not apply.

Unfortunately this issue is present on most resolutions other than the largest 1920x1200, which makes the majority of text difficult to read when next to a larger monitor, so is not an acceptable solution for my preferred setup.

I suspect this is an issue with the driver, in which case I can happily go and fish around in the kernel bugzilla or mailing lists, or if it is the hardware setup on this particular laptop, in which case I will consider returning it.

Look in you desktop setting for its scaling config so that the text is bigger then you do not need to change resolution.

As in the 100%/200% choice? Unfortunately this does not seem to have any affect when applied to just the built-in display, but also making the change to 200% on the external display does give larger text on both displays - but far too large for the external display. This could be another bug, but does remove it as an option.