checkpatch: fix false positive on empty block comment lines

To avoid false positives in presence of SPDX-License-Identifier in
networking files it is required to increase the leeway for empty block
comment lines by one line.

For example, checking drivers/net/loopback.c which starts with

    // SPDX-License-Identifier: GPL-2.0-or-later
    /*
     * INET          An implementation of the TCP/IP protocol suite for the LINUX

rsults in an unnecessary warning

    WARNING: networking block comments don't use an empty /* line, use /* Comment...
    +/*
    + * INET                An implementation of the TCP/IP protocol suite for the LINUX

Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Joe Perches <joe@perches.com>
Cc: Bartłomiej Żolnierkiewicz  <b.zolnierkie@samsung.co>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lkml.kernel.org/r/20201006083509.19934-1-l.stelmach@samsung.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 8a5f036..e1ddcaf 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3464,7 +3464,7 @@ sub process {
                if ($realfile =~ m@^(drivers/net/|net/)@ &&
                    $prevrawline =~ /^\+[ \t]*\/\*[ \t]*$/ &&
                    $rawline =~ /^\+[ \t]*\*/ &&
-                   $realline > 2) {
+                   $realline > 3) { # Do not warn about the initial copyright comment block after SPDX-License-Identifier
                        WARN("NETWORKING_BLOCK_COMMENT_STYLE",
                             "networking block comments don't use an empty /* line, use /* Comment...\n" . $hereprev);
                }