nouveau: DRM: GPU lockup - switching to software fbcon

[Sergey Senozhatsky]

5.2.0-rc4-next-20190613

dmesg

 nouveau 0000:01:00.0: DRM: GPU lockup - switching to software fbcon
 nouveau 0000:01:00.0: fifo: SCHED_ERROR 0a [CTXSW_TIMEOUT]
 nouveau 0000:01:00.0: fifo: runlist 0: scheduled for recovery
 nouveau 0000:01:00.0: fifo: channel 5: killed
 nouveau 0000:01:00.0: fifo: engine 6: scheduled for recovery
 nouveau 0000:01:00.0: fifo: engine 0: scheduled for recovery
 nouveau 0000:01:00.0: firefox[476]: channel 5 killed!
 nouveau 0000:01:00.0: firefox[476]: failed to idle channel 5 [firefox[476]]

It lockups several times a day. Twice in just one hour today.
Can we fix this?

	-ss