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

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Mar 06, 2025 at 10:24:56AM -0500, Jim Quinlan wrote:
> On Tue, Mar 4, 2025 at 9:49 AM Jim Quinlan <james.quinlan@broadcom.com> wrote:
> > On Mon, Mar 3, 2025 at 1:40 PM Bjorn Helgaas <helgaas@kernel.org> 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@broadcom.com>
> > > > ---
> > > >  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.
> 
> Manivannan stated that this series has already been merged.  So shall
> I implement your comments with a commit sometime in the future?

Sorry, I should have mentioned this would be something possible for
the future.  This current series is all set to go.

Bjorn