Benjamin,

On Wed, Mar 21, 2018 at 12:32 AM, Benjamin Warnke
[off-list ref] wrote:

Ok, I will use

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2018 Benjamin Warnke [off-list ref]
...

at the top of my files instead of that boilerplate text. And

MODULE_LICENSE("GPL");

at the bottom of the module-files.

<snip>

I used the file "crypto/lz4.c" - since it is a compression algorithm too - as an example of how to format the licensing text.
Unfortunately there is the same 'error'.
I fixed this error in all of my files in all patches.

Actually to be consistent if you want to use GPL-2-0 (and not "or
later") you should use:

1. at the top, for a c. file:
// SPDX-License-Identifier: GPL-2.0

or for a .h file:
/* SPDX-License-Identifier: GPL-2.0 */

The doc explains it all. Including the comment style (a topic that has
been discussed also on list quite bit: Linus had the final word there)

2. and in your MODULE_LICENSE macro:

MODULE_LICENSE("GPL v2");

.... because a MODULE_LICENSE("GPL"); would mean GPL-2.0+ (e.g. or any
later version) and this would not match your top level license tag.

I know this may seem confusing, but there is little hope we can change
the MODULE_LICENSE tags that are used by many external module loaders.
Comments in module.h explain it all.

-- 
Cordially
Philippe Ombredanne