Do you have the firmware loaded (also needed for DPM) or have no 3D acceleration? What does "glxinfo | grep renderer" report?

Yes, firmware is loaded by radeon driver. And renderer is: "OpenGL renderer string: Gallium 0.4 on AMD CAICOS"

When it says "R5 230 OEM", it means it, in case anyone was hoping to buy one from newegg or something. I purchased this R5 230 and it doesn't work properly as of linux-libre 4.11. No 3D acceleration, VESA drivers only - so it'll work if you've got only one display and no 3D needs, but otherwise you're in a pickle. If you're not sure if it's the aforementioned "OEM" version, probably best to look for something different.

Having just purchased a Radeon HD 6450 after the R5 230 failed to work, I can confirm that it doesn't work properly with a libre kernel. Firmware fails to load, all connected displays show the same output, and the output is frequently corrupt. 3D acceleration does not work. Tested with current GuixSD. Did you make sure that no nonfree sources were enabled in Debian when you tested this?

- Requires proprietary firmware ("Yes, firmware is loaded by radeon driver" - "with a libre kernel [f]irmware fails to load"). - Multiple reports of device not working properly. - People are spending money to find out it doesn't work with 3d acceleration. My suggestion is that this device should be marked as working with no 3d acceleration/VESA only.

Thanks, I've edited the record to note as "works, but without 3D acceleration".