Re: [PATCH v2 4/8] PCI: brcmstb: Fix error path upon call of regulator_bulk_get()

[Jim Quinlan]

On Mon, Mar 3, 2025 at 1:40 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>
> On Fri, Feb 14, 2025 at 12:39:32PM -0500, Jim Quinlan wrote:
> > If regulator_bulk_get() returns an error, no regulators are created and we
> > need to set their number to zero.  If we do not do this and the PCIe
> > link-up fails, regulator_bulk_free() will be invoked and effect a panic.
> >
> > Also print out the error value, as we cannot return an error upwards as
> > Linux will WARN on an error from add_bus().
> >
> > Fixes: 9e6be018b263 ("PCI: brcmstb: Enable child bus device regulators from DT")
> > Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
> > ---
> >  drivers/pci/controller/pcie-brcmstb.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > index e0b20f58c604..56b49d3cae19 100644
> > --- a/drivers/pci/controller/pcie-brcmstb.c
> > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > @@ -1416,7 +1416,8 @@ static int brcm_pcie_add_bus(struct pci_bus *bus)
> >
> >               ret = regulator_bulk_get(dev, sr->num_supplies, sr->supplies);
> >               if (ret) {
> > -                     dev_info(dev, "No regulators for downstream device\n");
> > +                     dev_info(dev, "Did not get regulators; err=%d\n", ret);
> > +                     pcie->sr = NULL;
>
> Is alloc_subdev_regulators() buying us something useful?  It seems
> like it would be simpler to have:
>
>   struct brcm_pcie {
>     ...
>     struct regulator_bulk_data supplies[3];
>     ...
>   };
>
> I think that's what most callers of devm_regulator_bulk_get() do.

Ack.

Jim Quinlan
Broadcom STB/CM
>
> >                       goto no_regulators;
> >               }
> >
> > --
> > 2.43.0
> >

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