Dear Leo,
In message 20200706023510.GB2522@andestech.com you wrote:
I am Leo, just recently joined the community. and been picking up the guide line of uboot's development.
I am a bit curious about the policy on the cover letter of patchsets. Is cover letter mandatory ?
No, it is not really mandatoryh, but strongl recommended for patch series.
IMHO, making it mandatory, especially on patchsets that consist of more than 1 patch, is more than useful and of great advantages.
For single patches a cover letter usually makes little sense.
- Making patches clearer for peer and maintainer review
...
- Helping the author better organize the patchset
...
In all, I think it would be nice to write cover letter to introduce the work.
All your arguments make a lot of sense, indeed.
If I miss anything or misunderstand anything please let me know, thanks in advance.
Please keep in mind that an inherent property of the cover letter is that it is NOT part of the patches itself, i. e. it helps only during the review process, but not any time later when someone tries to understand the code from reading the git commit logs.
So the essential information to understand the purpose and the implementation (and ideally also how it has been tested / can be tested) should always be part of the commit messages itself.
THe cover letter can summarize such information and provide the overview information for a patch series. Also it should commet on the changes between versions of the patch series, if these are needed (especially when major rework is done between submissions).
But it is only supplementary information which gets lost when the patches are pulled into the git repository.
Best regards,
Wolfgang Denk