Re: [PATCH v4 2/2] dma: Add Xilinx AXI Central Direct Memory Access Engine driver support

[Michal Simek]

On 06/09/2015 01:59 PM, Paul Bolle wrote:
> On Tue, 2015-06-09 at 12:41 +0200, Michal Simek wrote:
>> On 06/09/2015 10:15 AM, Paul Bolle wrote:
>>> Mistakes I've seen made since I started checking this stuff (a few
>>> months ago):
>>> - typos in the license ident, say "GPLv2", "GPL V2", or "BSD": generates
>>> a warning when module is loaded and taints kernel. People still get this
>>> wrong. A test in checkpatch for these typos was submitted a while ago,
>>> but it never got added;
>>
>> Any reason for that? just lost or any problem ?
> 
> Submitter lost interest, I guess. Check
> https://lkml.org/lkml/2015/5/22/279 and note that there was no response.

will see.


>>> - not adding MODULE_LICENSE() to a module: also generates a warning when
>>> module is loaded and taints kernel. People still get this wrong;
>>> - adding MODULE_LICENSE() to built-in only code: pointless at best, and
>>> annoying for reviewers ("Hey, did the submitter intend to write built-in
>>> only code or modular code?");
>>> - using "Dual BSD/GPL" but not a trace of the BSD license blurb in
>>> sight, while adding that blurb is one of the very few requirements this
>>> license actually has;
>>> - license mismatch, say comment blurb states "GPL v2 (or later)" but
>>> MODULE_LICENSE() ident states "GPL v2" only (or vice versa): very easy
>>> mistake to make, happens once or twice a week.  
>>
>> What do you mean by vice versa?
>> GPL v2 header and MODULE_LICENSE("GPL") should be fine right?
> 
> Not really. The license in the comment at the top of the file is just
> GPL v2, while the MODULE_LICENSE ident adds "or later" and thus the
> right to "uplicense". So which is it: just "GPL v2" or "GPL v2 (or
> later)"? Can't say in that case.

ok. Will check all our drivers we have to get it synchronized but I
expect that a lot of drivers have problems there.

>>> Did I miss anything in that list?
>>
>> I think you miss MODULE_ALIAS problems.
>> https://lkml.org/lkml/2014/3/17/301
> 
> That's outside of the license stuff, but thanks for thye pointer anyway.
> 
>>> I'm afraid that most of the above can only be caught reliably by
>>> attention to detail by submitters and reviewers. That's a pity, because
>>> checking for that stuff is about as boring as it gets. (What does that
>>> say about me?)
>>
>> yep. I have never looked at the details about these license module
>> stuff. But definitely great to have this list - will record it and keep
>> my eye on our xilinx drivers.
>>
>> BTW: Some time ago we discussed SPDX License Identifier which could
>> simplify license checking.
>> https://lkml.org/lkml/2014/2/21/21
> 
> I think I saw that fly by. Wasn't that idea shot down?

Not sure about current status.

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform

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