Created attachment 1199132 [details]
Display settings

Description of problem:
After kernel upgrade, my screen is unrecognized. It is marked as "Unknown display" in Settings, the resolution is wrong and the graphic performance is very low.

There are only two available resolutions by now :
- 1024x768 (4:3)
- 800x600 (4:3)
Before this upgrade, there were plenty other resolutions, including the ideal one for my screen which is 1366x768, now unavailable.

As mentioned before, my graphic performance is now very low. As an example, Minecraft used to run at ~60FPS, but now only runs at ~6FPS.

Version-Release number of selected component (if applicable): the bug appeared first when I upgraded to kernel-4.6.7-300.fc24.x86_64 and is still present in kernel-4.7.2-201.fc24.x86_64.

The last kernel without this bug is kernel-4.5.5-300.fc24.x86_64, which I'll keep installed and use as my default kernel until the problem is resolved.

Additional info:
My graphic card is an ATI Radeon HD 7670M.
In "lspci", it is named "01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Thames [Radeon HD 7500M/7600M Series]".
Result of "uname -a" with the last kernel with this bug : "Linux fedora-l850-15z 4.7.2-201.fc24.x86_64 #1 SMP Fri Aug 26 15:58:40 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux".

I also attached a screenshot of the display settings.