Created attachment 127916 [details]
dmesg

After Fedora updated the kernel to 4.8 my discrete AMD GPU stopped working. Even the most simple commands like DRI_PRIME=1 glxinfo produce:
radeon: Failed to allocate virtual address for buffer:
radeon:    size      : 65536 bytes
radeon:    alignment : 4096 bytes
radeon:    domains   : 4
radeon:    va        : 0x0000000000800000
radeon: Failed to deallocate virtual address for buffer:
radeon:    size      : 65536 bytes
radeon:    va        : 0x800000
..........
radeonsi: Failed to create a context.
X Error of failed request:  GLXBadContext
  Major opcode of failed request:  154 (GLX)
  Minor opcode of failed request:  6 (X_GLXIsDirect)
  Serial number of failed request:  44
  Current serial number in output stream:  43

Dmesg from booting and attempting to run glxinfo is attached.

I managed to bisect it to:
b817634276f7f68c9d1d6d4a27117ff3c2f16956 is the first bad commit
commit b817634276f7f68c9d1d6d4a27117ff3c2f16956
Author: Alex Deucher <alexander.deucher@amd.com>
Date:   Tue Aug 9 00:21:45 2016 -0400

    Revert "drm/radeon: work around lack of upstream ACPI support for D3cold"
    
    This reverts commit bdfb76040068d960cb9e226876be8a508d741c4a.
    
    Now that d3cold is upstream, there is no more need for this workaround.

Reverting this commit from top of the current linux git fixes things for me.
This might be duplicate of bug 98505, however this is with radeon driver instead of the amdgpu, so filling separately.

This is Lenovo G50-80 laptop 
discrete GPU: 04:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Sun XT [Radeon HD 8670A/8670M/8690M / R5 M330 / M430] (rev ff)
integrated GPU: 00:02.0 VGA compatible controller: Intel Corporation HD Graphics 5500 (rev 09)
Mesa: 12.0.3-2.fc24
Libdrm: 2.4.71-2.fc24