Re: [PATCH 01/37] PCI/MSI: Add Devres managed IRQ vectors allocation

Shawn Lin
2026-02-24T08:36:38Z

在 2026/02/24 星期二 15:47, Philipp Stanner 写道:
> On Tue, 2026-02-24 at 10:08 +0800, Shawn Lin wrote:
>> 在 2026/02/24 星期二 8:04, Jakub Kicinski 写道:
>>> On Mon, 23 Feb 2026 23:29:40 +0800 Shawn Lin wrote:
>>>> pcim_alloc_irq_vectors() and pcim_alloc_irq_vectors_affinity() are created for
>>>> pci device drivers which rely on the devres machinery to help cleanup the IRQ
>>>> vectors.
>>>
>>> If you can please add this API with just a few users, and then convert
>>> remaining users via the subsystem trees in the next cycle.
>>> There's no need to risk wasting maintainer time on conflicts with
>>> conversions like this.
>>
>> Thanks for the suggestion, Jakub. I have little experience with
>> cross-subsystem cleanups like this, so your suggestion is very helpful.
>
>
> When I removed the hybrid nature of pci_request_region() et al., I
> concluded that there were so few users that doing them all in one run
> was sufficient.
>
> For larger reworks, like removing pcim_iomap_table(), a slower step-by-
> step strategy is necessary for the reasons that Jakub details.
>
> It is then smart to omit an easy to port subsystem / driver for the
> ultimate patch series where one then removes the hybrid behavior from
> PCI itself, after porting the last driver.
>
> In general, as Jakub details, those step-by-step cleanups are a bit
> safer, since you can proof valid behavior early on and in case of an
> explosion they are very easy to revert.
>

Thank you, Philipp. I wish I had attended your talk at FOSDEM 2025 on
removing pcim_iomap_table earlier. This first version was perhaps a bit
too aggressive. For v2, I think the plan should start with addressing
the switchtec and vmd drivers, since both of those, along with the new
API additions, can be handled entirely within the PCI subsystem scope.

>
> P.
>