External monitors and backlight control don't work

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hansegucker
Posts: 1
Joined: 2021-06-19 07:01

External monitors and backlight control don't work

#1 Post by hansegucker »

Hi everyone,

I have installed a Debian Sid with kernel version 5.10.0-7-amd64 on my new ThinkPad device. When I connect external monitors via the Lenovo USB-C dock or even the internal HDMI socket, they are not detected by GNOME or xrandr. Additionally, changing the brightness of the internal display doesn't work (tested with keyboard shortcuts, GNOME settings, and manually setting /sys/class/backlight/acpi_video0/brightness).

When I start a live system via a USB stick, everything works fine.

Here you can find some basic system information:

ThinkPad E14 Gen 3 (AMD Ryzen 5500U)

Code: Select all

lspci
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Root Complex
00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD] Renoir IOMMU
00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge
00:02.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe GPP Bridge
00:02.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe GPP Bridge
00:02.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe GPP Bridge
00:02.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe GPP Bridge
00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy Host Bridge
00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Renoir Internal PCIe GPP Bridge to Bus
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 51)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 51)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 5
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 6
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Renoir Device 24: Function 7
01:00.0 Non-Volatile memory controller: SK hynix Device 174a
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 10)
03:00.0 Network controller: Realtek Semiconductor Co., Ltd. Device 8852
04:00.0 Non-Volatile memory controller: Intel Corporation SSD 660P Series (rev 03)
05:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Lucienne (rev c2)
05:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Device 1637
05:00.2 Encryption controller: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) Platform Security Processor
05:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Renoir USB 3.1
05:00.4 USB controller: Advanced Micro Devices, Inc. [AMD] Renoir USB 3.1
05:00.5 Multimedia controller: Advanced Micro Devices, Inc. [AMD] Raven/Raven2/FireFlight/Renoir Audio Processor (rev 01)
05:00.6 Audio device: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) HD Audio Controller
I am quite unsure how to debug such a problem and how to collect proper information for this purpose. If you can help me with this, I will be very glad.

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