Hello everyone,

I got a brand new T14 on which I run ArchLinux with X11.

I want to setup a triple screen with the native HDMI plus an USB-C hub. But I didn't succed to achieve it.

Everything is OK when I just have only one screen connected (see below with the HDMI2 on xrandr).

Then when i connect the second one, the HDMI2 got disconnect and DP2 connected but without rendering any one of them.

Do anybody achieve such a settings like this T14 ? 

Thanks in advance,

A.

Here some commands results : 

 ❯  lsusb
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 05e3:0626 Genesys Logic, Inc. USB3.1 Hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 010: ID 06cb:00bd Synaptics, Inc. Prometheus MIS Touch Fingerprint Reader
Bus 001 Device 008: ID 04ca:7070 Lite-On Technology Corp. Integrated Camera
Bus 001 Device 006: ID 046d:c539 Logitech, Inc. USB Receiver
Bus 001 Device 004: ID 0c45:767d Microdia USB DEVICE
Bus 001 Device 009: ID 046d:0892 Logitech, Inc. OrbiCam
Bus 001 Device 007: ID 177a:963d EXPSM USB Billboard Device
Bus 001 Device 005: ID 1a40:0801 Terminus Technology Inc. USB 2.0 Hub
Bus 001 Device 003: ID 05e3:0610 Genesys Logic, Inc. Hub
Bus 001 Device 011: ID 8087:0026 Intel Corp.
Bus 001 Device 002: ID 058f:9540 Alcor Micro Corp. AU9540 Smartcard Reader
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

 ❯  lspci
00:00.0 Host bridge: Intel Corporation Device 9b61 (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 02)
00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Sub
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:12.0 Signal processing controller: Intel Corporation Comet Lake Thermal Subsytem
00:14.0 USB controller: Intel Corporation Device 02ed
00:14.2 RAM memory: Intel Corporation Device 02ef
00:14.3 Network controller: Intel Corporation Wireless-AC 9462
00:16.0 Communication controller: Intel Corporation Comet Lake Management Engine Interface
00:1c.0 PCI bridge: Intel Corporation Device 02b8 (rev f0)
00:1c.4 PCI bridge: Intel Corporation Device 02bc (rev f0)
00:1d.0 PCI bridge: Intel Corporation Device 02b0 (rev f0)
00:1d.4 PCI bridge: Intel Corporation Device 02b4 (rev f0)
00:1f.0 ISA bridge: Intel Corporation Device 0284
00:1f.3 Audio device: Intel Corporation Device 02c8
00:1f.4 SMBus: Intel Corporation Device 02a3
00:1f.5 Serial bus controller [0c80]: Intel Corporation Comet Lake SPI (flash) Controller
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (10) I219-V
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01)
03:00.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
04:00.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
04:01.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
04:02.0 PCI bridge: Intel Corporation JHL6240 Thunderbolt 3 Bridge (Low Power) [Alpine Ridge LP 2016] (rev 01)
05:00.0 System peripheral: Intel Corporation JHL6240 Thunderbolt 3 NHI (Low Power) [Alpine Ridge LP 2016] (rev 01)
2b:00.0 USB controller: Intel Corporation JHL6240 Thunderbolt 3 USB 3.1 Controller (Low Power) [Alpine Ridge LP 2016] (rev 01)
2e:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983

❯  xrandr (with the first connected)

Screen 0: minimum 8 x 8, current 4031 x 1920, maximum 32767 x 32767
eDP1 connected primary 1920x1080+2111+0 (normal left inverted right x axis y axis) 310mm x 170mm
   1920x1080     60.02*+  59.93    48.00
   1680x1050     59.88
   1400x1050     59.98
   1600x900      60.00    59.95    59.82
   1280x1024     60.02
   1400x900      59.96    59.88
   1280x960      60.00
   1368x768      60.00    59.88    59.85
   1280x800      59.81    59.91
   1280x720      59.86    60.00    59.74
   1024x768      60.00
   1024x576      60.00    59.90    59.82
   960x540       60.00    59.63    59.82
   800x600       60.32    56.25
   864x486       60.00    59.92    59.57
   640x480       59.94
   720x405       59.51    60.00    58.99
   640x360       59.84    59.32    60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 connected 1080x1920+0+0 right (normal left inverted right x axis y axis) 520mm x 290mm
   1920x1080     60.00*+  50.00    59.94
   1680x1050     59.88
   1600x900      60.00
   1280x1024     75.02    60.02
   1440x900      59.90
   1280x800      59.91
   1152x864      75.00
   1280x720      60.00    50.00    59.94
   1024x768      75.03    70.07    60.00
   832x624       74.55
   800x600       72.19    75.00    60.32    56.25
   720x576       50.00
   720x480       60.00    59.94
   640x480       75.00    72.81    66.67    60.00    59.94
   720x400       70.08
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

❯  xrandr (with the two screens connected)

Screen 0: minimum 8 x 8, current 4031 x 1920, maximum 32767 x 32767
eDP1 connected primary 1920x1080+2111+0 (normal left inverted right x axis y axis) 310mm x 170mm
   1920x1080     60.02*+  59.93    48.00
   1680x1050     59.88
   1400x1050     59.98
   1600x900      60.00    59.95    59.82
   1280x1024     60.02
   1400x900      59.96    59.88
   1280x960      60.00
   1368x768      60.00    59.88    59.85
   1280x800      59.81    59.91
   1280x720      59.86    60.00    59.74
   1024x768      60.00
   1024x576      60.00    59.90    59.82
   960x540       60.00    59.63    59.82
   800x600       60.32    56.25
   864x486       60.00    59.92    59.57
   640x480       59.94
   720x405       59.51    60.00    58.99
   640x360       59.84    59.32    60.00
DP1 disconnected (normal left inverted right x axis y axis)
DP2 connected (normal left inverted right x axis y axis)
   1920x1080     60.00 +  50.00    59.94
   1680x1050     59.88
   1680x945      60.02
   1400x1050     59.95
   1600x900      60.00
   1280x1024     75.02    60.02
   1440x900      74.98    59.90
   1280x960      60.00
   1366x768      59.79
   1360x768      60.02
   1280x800      74.93    59.91
   1152x864      75.00
   1280x768      74.89    59.99
   1280x720      60.00    59.94
   1024x768      75.03    70.07    60.00
   1024x576      59.97
   832x624       74.55
   800x600       72.19    75.00    60.32    56.25
   720x576       50.00
   848x480       60.00
   720x480       60.00    59.94
   640x480       75.00    72.81    66.67    60.00    59.94
   720x400       70.08
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected 1080x1920+0+0 right (normal left inverted right x axis y axis) 0mm x 0mm
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Intel model T14? From the User Manual:

Thanks for your answer. Yes the Intel one.

Changing the priority dosn't change the behavior which is well describe in the manual.

At the end priority doesn't matter for me. I want both working :)

OK I thought the manual was clear, you can't have that. The options you have for external monitors on the ThinkPad USB-C Gen 2 dock are listed under the DisplayPort 1.2 table, here. You need a USB-C dock, not a hub.

It's hard to hear but OK.

Thanks,

A.