Xid 50 + X11 lockup with driver v375.26

I just got a X11 lockup, with “Xid 50” reported in the system log:

Dec 29 10:22:05 localhost klogd: NVRM: GPU at PCI:0000:01:00: GPU-9cf0476e-4dbe-8c0f-4352-800be7075c41
Dec 29 10:22:05 localhost klogd: NVRM: Xid (PCI:0000:01:00): 50,  L2 -> L1

The Second Life viewer was running in the background while I was editing a text file (with Nedit) when it happened…

I’m also attaching the traditional nvidia-bug-report.log.gz file.
nvidia-bug-report.log.gz (219 KB)