I have a new Lenovo Yoga Slim 7 with an AMD Ryzen 5 6600HS processor. This processor has a Radeon 660M integrated graphics controller, and I don't have a dedicated GPU. I have several issues which I think are all or in part related to driver issues:

  1. High CPU usage when watching a YouTube video.
  2. http://webglsamples.org/aquarium/aquarium.html reaches 20FPS in Firefox (500 fish), which is already 27FPS on my much older (2015) system with an integrated HD graphics 5500 card.
  3. LCD backlight is fixed to the maximum. /sys/class/backlight is empty. With the kernel setting acpi_backlight=vendor there is a /sys/class/backlight/ideapad entry and when I try to change the backlight level the changes are registered in actual_brightness but there is no effect on the screen.
  4. xrandr only recognizes one mode (2880x1800 @ 91Hz), while at least a lower refresh rate should be available. Also xrandr "fails to get size of gamma" (see output below).
  5. lspci incorrectly recognizes the integrated GPU as Radeon 680M, this should be 660M (see output below).
  6. radeontop fails to find DRM devices and measures only zero values.
  7. glxgears has very high framerate (thousands of FPS), not close to screen refresh rate. On my old system it says "Running synchronized to the vertical refresh" and runs at 51FPS. Perhaps this means that the system cannot determine the screen refresh rate correctly (although xrandr can...).

This is a fresh install of the alpha1 release candidate for Debian Bookworm with the GNOME desktop environment. I used an ISO with non-free firmware from https://cdimage.debian.org/cdimage/unofficial/non-free/cd-including-firmware/bookworm_di_alpha1+nonfree/amd64/iso-cd, dated 20 September 2022.

I also installed firmware-amd-graphics_20210818-1_all.deb from that ISO (following https://wiki.debian.org/AtiHowTo), although I'm not sure that's the right thing to do for integrated GPUs. I had to copy the yellow_carp firmware files to /lib/firmware/amdgpu manually, following https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1019847.

I don't normally deal with driver issues. How can I get the graphics to work properly?


  • The X log complains that /dev/dri/card0/ does not exist. This is correct; there is no /dev/dri on my system.
  • dmesg has no mention of amdgpu so perhaps it is not loaded at all?
  • I would have expected the non-free ISO to automatically install the amdgpu driver if needed, so the fact that I had to install it manually may also already suggest that the card is not recognized properly.

Relevant outputs (let me know if you need more):

$ lspci -nn | grep VGA
32:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Rembrandt [Radeon 680M] [1002:1681] (rev 03)
$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 2880 x 1800, current 2880 x 1800, maximum 2880 x 1800
default connected primary 2880x1800+0+0 0mm x 0mm
   2880x1800     91.00* 
$ sudo radeontop -d -
Failed to find DRM devices: error 2 (No such file or directory)
Failed to open DRM node, no VRAM support.
Dumping to -, until termination.
1676540729.241609: bus 32, gpu 0.00%, ee 0.00%, vgt 0.00%, ta 0.00%, sx 0.00%, sh 0.00%, spi 0.00%, sc 0.00%, pa 0.00%, db 0.00%, cb 0.00%
$ glxgears
24119 frames in 5.0 seconds = 4823.791 FPS
24445 frames in 5.0 seconds = 4888.914 FPS


1 Answer 1


It turns out I still had nomodeset as a kernel parameter. Removing it fixed the issues.

  • The WebGL aquarium sample now runs at 60FPS with 10,000 fish (was 20FPS with 500).
  • The LCD backlight works out of the box; no acpi_backlight parameter needed.
  • xrandr now recognizes different modes and does not complain about gamma.
  • radeontop correctly reports measurements.
  • glxgears fixes the frame rate to the vertical refresh rate.

Only lspci still sees the card as 680M rather than 660M, but I guess it's not a problem.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .