==========
checkpatch - FAILED

ERROR: lockdep_no_validate class is reserved for device->mutex.
#173: FILE: net/l2tp/l2tp_core.c:1602:
+		lockdep_set_novalidate_class(&sk->sk_lock.slock);

WARNING: The commit message has 'Call Trace:', perhaps it also needs a 'Fixes:' tag?

total: 1 errors, 1 warnings, 0 checks, 16 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Commit a94db1138bab ("RFC: l2tp: how to fix nested socket lockdep splat") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE GIT_COMMIT_ID MACRO_ARG_REUSE NO_AUTHOR_SIGN_OFF

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.