Re: [PATCH] mux: add SPDX identifiers to all mux source files

[Philippe Ombredanne <pombredanne@nexb.com>]

Dear Philipp,

On Fri, Dec 8, 2017 at 10:43 AM, Philipp Zabel <p.zabel@pengutronix.de> wrote:
> Hi Peter,
>
> On Thu, 2017-12-07 at 22:08 +0100, Peter Rosin wrote:
>> Remove all free-text license texts.
>>
>> This is done on a quest to remove the 700+ different ways that files in
>> the kernel describe the GPL license text.
>>
>> No copyright headers or other non-license-description text was removed.
>>
>> Signed-off-by: Peter Rosin <peda@axentia.se>
>> ---
>>
>> Hi Philipp,
>>
>> I assume this is ok with you for the mmio file, but asking just in case...
> [...]
>> diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
>> index 37c1de359a70..935ac44aa209 100644
>> --- a/drivers/mux/mmio.c
>> +++ b/drivers/mux/mmio.c
>> @@ -1,11 +1,8 @@
>> +// SPDX-License-Identifier: GPL-2.0
>
> Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
>
>>  /*
>>   * MMIO register bitfield-controlled multiplexer driver
>>   *
>>   * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
>> - *
>> - * This program is free software; you can redistribute it and/or modify
>> - * it under the terms of the GNU General Public License version 2 as
>> - * published by the Free Software Foundation.
>>   */
>>
>>  #include <linux/bitops.h>
>> diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h
>> index ea96d4c82be7..5fc6bb2fefad 100644
>> --- a/include/linux/mux/consumer.h
>> +++ b/include/linux/mux/consumer.h
>> @@ -1,13 +1,10 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>
> Is there a system to the different comment styles in c the files vs in
> the headers?

The issue is that some includes are included in assembly. And believe
it or not it makes the build crash in some cases! Greg and Thomas
banged their head on this a bit and decided to go for now with /**/
for includes (and // for the C files which is Linus' preferred style):
he explained why he wants the // comment style and a first line
location on the list too. I think Linus (semi reluctantly) agreed to
the exception for includes because there is no immediate easy way out.
I am sure this could be cleaned up overtime... It feels a tad weird to
include a in.h in a .s ;)

For  reference please check Linus [1][2][3], Thomas [4] and Greg [5]
comments on the topic.

Jonathan also wrote a nice background article on the SPDXification
topic at LWN [6]

[1] https://lkml.org/lkml/2017/11/2/715
[2] https://lkml.org/lkml/2017/11/25/125
[3] https://lkml.org/lkml/2017/11/25/133
[4] https://lkml.org/lkml/2017/11/2/805
[5] https://lkml.org/lkml/2017/10/19/165
[6] https://lwn.net/Articles/739183/

-- 
Cordially
Philippe Ombredanne