WARNING: line length of 102 exceeds 80 columns
#49: FILE: include/uapi/linux/if_ether.h:117:
+#define ETH_P_YT921X	0x9988		/* Motorcomm YT921x DSA [ NOT AN OFFICIALLY REGISTERED ID ] */

WARNING: please write a help paragraph that fully describes the config symbol with at least 4 lines
#61: FILE: net/dsa/Kconfig:193:
+config NET_DSA_TAG_YT921X
+	tristate "Tag driver for Motorcomm YT921x switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Motorcomm YT921x switches.
+

WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#81: 
new file mode 100644

WARNING: line length of 84 exceeds 80 columns
#122: FILE: net/dsa/tag_yt921x.c:37:
+#define  YT921X_TAG_RX_CMD(x)			FIELD_PREP(YT921X_TAG_RX_CMD_M, (x))

total: 0 errors, 4 warnings, 0 checks, 176 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 53fdc51a9dd4 ("net: dsa: tag_yt921x: add support for Motorcomm YT921x tags") 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.
total: 0 errors, 4 warnings, 0 checks, 176 lines checked