Re: [PATCH] docs: submitting-patches: Require base tree information

[Krzysztof Kozlowski <krzk@kernel.org>]

On 22/10/2026 09:25, Eric Biggers wrote:
> On Thu, Oct 22, 2026 at 08:57:55AM +0200, Krzysztof Kozlowski wrote:
>> On 21/10/2026 18:32, Laurent Pinchart wrote:
>>> On Wed, Oct 21, 2026 at 01:55:37PM +0200, Krzysztof Kozlowski wrote:
>>>>
>>>>> there's no base-commit?  Including any historical patch (from
>>>>> months/years ago), patches with dependencies, etc.
>>>>
>>>> Dependency is something else, but for every other patch:
>>>> 1. For testing/CI: you apply on top of next
>>>> 2. Every other case the maintainer knows where to apply it, because it
>>>> is his HEAD of next-branch.
>>>>
>>>> I am repeating myself, but I really had no single problem of lack of
>>>> knowledge where to apply a patch as a maintainer or reviewer of some
>>>> subsystem, thus maybe I do not understand the actual problem you are
>>>> experiencing.
>>>
>>> When I review patches, I often need to apply them to a tree, mainly to
>>> see the context, but sometimes also to test them. I have encountered
>>> many cases where the patch wouldn't apply on the current for-next branch
>>> of the relevant subsystem. That's often because the patch had
>>> dependencies. When I'm lucky they are listed manually in the cover
>>> letter with a link to a branch, but that's far from being the common
>>> case. I then have to ask the submitter to provide a branch, or enough
>>> information to recreate a branch. Having base information (base-commit,
>>> prerequisite-patch-id, and possibly base-tree) would save me quite some
>>> time.
>>>
>>> I understand your concern about maintainers cherry-picking and sometimes
>>> introducing issues as a result. In that case I also prefer asking the
>>> submitter to rebase, retest, and resubmit. That's not what I want to use
>>> base information for, in my case it helps with the review process.
>>
>> That's valid and for 95% (guessing the number...) of cases will be
>> solved by having linux-next as a base, thus requiring the base
>> information is redundant. It's just linux-next.
> 
> linux-next changes every day, so "It's just linux-next" is ambiguous.
> 
> Without base-commit, the workaround ends up being to use the date the
> patch was sent and various other information to try to guess a base
> commit.  That's time-consuming and unreliable.

No, you just apply to the latest next. You don't guess. We speak about
the case of reviewer, so person working with the kernel, thus probably
having not-so-old linux-next available. If the next use as base is old
it won't help you at all, because you might not even have it in your tree.

Best regards,
Krzysztof