Re: [PATCH v3] PCI/pwrctrl: Move pci_pwrctrl_create_device() definition to drivers/pci/pwrctrl/

[Bartosz Golaszewski]

On Mon, Jun 16, 2025 at 3:16 PM Lukas Wunner <lukas@xxxxxxxxx> wrote:
>
> On Mon, Jun 16, 2025 at 06:07:48PM +0530, Manivannan Sadhasivam wrote:
> > On Mon, Jun 16, 2025 at 08:21:20PM +0800, kernel test robot wrote:
> > >    ld: drivers/pci/probe.o: in function `pci_scan_single_device':
> > > >> probe.c:(.text+0x2400): undefined reference to `pci_pwrctrl_create_device'
> >
> > Hmm, so we cannot have a built-in driver depend on a module...
> >
> > Bartosz, should we make CONFIG_PCI_PWRCTRL bool then? We can still allow the
> > individual pwrctrl drivers be tristate.
>
> I guess the alternative is to just leave it in probe.c.  The function is
> optimized away in the CONFIG_OF=n case because of_pci_find_child_device()
> returns NULL.  It's unpleasant that it lives outside of pwrctrl/core.c,
> but it doesn't occupy any space in the compiled kernel at least on non-OF
> (e.g. ACPI) platforms.
>

And there's a third option of having this function live in a separate
.c file under drivers/pci/pwrctl/ that would be always built-in even
if PWRCTL itself is a module. The best/worst of two worlds? :)

Bart