My dual monitor setup goes black and stays this way until reboot intermittently. This happens after my monitors work perfectly for days. Not sure how to fix this. GPUs are Dual AMD D300 GPU on a MacPro 6,1. I recently had to add the following code to Kernel parameters after kernel update to be able to get my computer to boot past a black screen on boot. I also show results from dmesg post crash

Kernel Parameters
Code:
radeon.si_support=0 radeon.cik_support=0 amdgpu.si_support=1 amdgpu.cik_support=1 showopts

DMESG

Code:
90219.866152] No iBFT detected.
[91946.588197] pcieport 0000:00:03.0: AER: Uncorrected (Non-Fatal) error received: id=0018
[91946.588222] pcieport 0000:00:03.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, id=0018(Requester ID)
[91946.588230] pcieport 0000:00:03.0:   device [8086:0e08] error status/mask=00004000/00000000
[91946.588235] pcieport 0000:00:03.0:    [14] Completion Timeout     (First)
[91946.588240] pcieport 0000:00:03.0: broadcast error_detected message
[91946.588243] pcieport 0000:00:03.0: AER: Device recovery failed
[91946.621762] pciehp 0000:00:03.0:pcie004: Slot(5-3): Link Down
[91946.621806] pcieport 0000:00:03.0: AER: Multiple Uncorrected (Fatal) error received: id=0018
[91946.621818] pcieport 0000:00:03.0: PCIe Bus Error: severity=Uncorrected (Fatal), type=Transaction Layer, id=0018(Requester ID)
[91946.621826] pcieport 0000:00:03.0:   device [8086:0e08] error status/mask=00004020/00000000
[91946.621831] pcieport 0000:00:03.0:    [ 5] Surprise Down Error   
[91946.621835] pcieport 0000:00:03.0:    [14] Completion Timeout     (First)
[91946.621842] pcieport 0000:00:03.0: broadcast error_detected message
[91946.621847] amdgpu 0000:06:00.0: device has no AER-aware driver
[91946.621850] snd_hda_intel 0000:06:00.1: device has no AER-aware driver
[91946.655322] pciehp 0000:00:03.0:pcie004: Slot(5-3): Link Up
[91946.803531] snd_hda_codec_hdmi hdaudioC2D0: Unable to sync register 0x2f0d00. -5
[91946.803542] snd_hda_codec_hdmi hdaudioC2D0: HDMI ATI/AMD: no speaker allocation for ELD
[91946.803547] snd_hda_codec_hdmi hdaudioC2D0: HDMI ATI/AMD: no speaker allocation for ELD
[91946.803551] snd_hda_codec_hdmi hdaudioC2D0: HDMI ATI/AMD: no speaker allocation for ELD
[91946.803555] snd_hda_codec_hdmi hdaudioC2D0: HDMI ATI/AMD: no speaker allocation for ELD
[91946.803558] snd_hda_codec_hdmi hdaudioC2D0: HDMI ATI/AMD: no speaker allocation for ELD
[91946.803562] snd_hda_codec_hdmi hdaudioC2D0: HDMI ATI/AMD: no speaker allocation for ELD
[91947.004922] [drm] amdgpu: finishing device.
[91947.642635] pcieport 0000:00:03.0: Root Port link has been reset
[91947.642645] pcieport 0000:00:03.0: AER: Device recovery failed
[91952.006677] [drm:atom_op_jump [amdgpu]] *ERROR* atombios stuck in loop for more than 5secs aborting
[91952.006743] [drm:amdgpu_atom_execute_table_locked [amdgpu]] *ERROR* atombios stuck executing D09C (len 75, WS 0, PS 0) @ 0xD0CB
[91957.010666] [drm:atom_op_jump [amdgpu]] *ERROR* atombios stuck in loop for more than 5secs aborting
[91957.010724] [drm:amdgpu_atom_execute_table_locked [amdgpu]] *ERROR* atombios stuck executing D0E8 (len 62, WS 0, PS 0) @ 0xD104
elproducto@FVSUSE:~>