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

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Tue, Mar 04, 2025 at 12:24:56PM -0500, Jim Quinlan wrote:
> On Tue, Mar 4, 2025 at 12:07 PM Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org> wrote:
> >
> > On Tue, Mar 04, 2025 at 11:55:05AM -0500, Jim Quinlan wrote:
> > > On Tue, Mar 4, 2025 at 10:03 AM Manivannan Sadhasivam
> > > <manivannan.sadhasivam@linaro.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);
> > > >
> > > > Why is this dev_info() instead of dev_err()?
> > >
> > > I will change this.
> > > >
> > > > > +                     pcie->sr = NULL;
> > > >
> > > > Why can't you set 'pcie->sr' after successfull regulator_bulk_get()?
> > >
> > > Not sure I understand -- it is already set before a  successful
> > > regulator_bulk_get() call.
> >
> > Didn't I say 'after'?
> 
> Sorry, I misinterpreted your question.  I can change it but it would
> just be churn because a new commit is going to refactor this function.
> However,
> I can set  pcie->num_regulators "after" in the new commit.
> 

If a new patch is going to change the beahvior, then I'm fine with it for now.
After all, this series is already merged.

- Mani

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