[PATCH v5 03/12] PCI: brcmstb: Use common error handling code in brcm_pcie_probe()

[Jim Quinlan]

On Tue, Aug 6, 2024 at 10:53 PM Manivannan Sadhasivam
<manivannan.sadhasivam at linaro.org> wrote:
>
> On Wed, Jul 31, 2024 at 06:28:17PM -0400, Jim Quinlan wrote:
> > o Move the clk_prepare_enable() below the resource allocations.
> > o Move the clk_prepare_enable() out of __brcm_pcie_remove() but
> >   add it to the end of brcm_pcie_remove().
> > o Add a jump target (clk_disable_unprepare) so that a bit of exception
> >   handling can be better reused at the end of this function implementation.
> > o Use dev_err_probe() where it makes sense.
> >
> > Signed-off-by: Jim Quinlan <james.quinlan at broadcom.com>
> > ---
> >  drivers/pci/controller/pcie-brcmstb.c | 34 ++++++++++++---------------
> >  1 file changed, 15 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > index c08683febdd4..7595e7009192 100644
> > --- a/drivers/pci/controller/pcie-brcmstb.c
> > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > @@ -1473,7 +1473,6 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
> >               dev_err(pcie->dev, "Could not stop phy\n");
> >       if (reset_control_rearm(pcie->rescal))
> >               dev_err(pcie->dev, "Could not rearm rescal reset\n");
> > -     clk_disable_unprepare(pcie->clk);
> >  }
> >
> >  static void brcm_pcie_remove(struct platform_device *pdev)
> > @@ -1484,6 +1483,7 @@ static void brcm_pcie_remove(struct platform_device *pdev)
> >       pci_stop_root_bus(bridge->bus);
> >       pci_remove_root_bus(bridge->bus);
> >       __brcm_pcie_remove(pcie);
> > +     clk_disable_unprepare(pcie->clk);
> >  }
> >
> >  static const int pcie_offsets[] = {
> > @@ -1613,31 +1613,26 @@ static int brcm_pcie_probe(struct platform_device *pdev)
> >
> >       pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
> >
> > -     ret = clk_prepare_enable(pcie->clk);
> > -     if (ret) {
> > -             dev_err(&pdev->dev, "could not enable clock\n");
> > -             return ret;
> > -     }
> >       pcie->rescal = devm_reset_control_get_optional_shared(&pdev->dev, "rescal");
> > -     if (IS_ERR(pcie->rescal)) {
> > -             clk_disable_unprepare(pcie->clk);
> > +     if (IS_ERR(pcie->rescal))
> >               return PTR_ERR(pcie->rescal);
> > -     }
> > +
> >       pcie->perst_reset = devm_reset_control_get_optional_exclusive(&pdev->dev, "perst");
> > -     if (IS_ERR(pcie->perst_reset)) {
> > -             clk_disable_unprepare(pcie->clk);
> > +     if (IS_ERR(pcie->perst_reset))
> >               return PTR_ERR(pcie->perst_reset);
> > -     }
> >
> > -     ret = reset_control_reset(pcie->rescal);
> > +     ret = clk_prepare_enable(pcie->clk);
> >       if (ret)
> > -             dev_err(&pdev->dev, "failed to deassert 'rescal'\n");
> > +             return dev_err_probe(&pdev->dev, ret, "could not enable clock\n");
> > +
> > +     ret = reset_control_reset(pcie->rescal);
> > +     if (dev_err_probe(&pdev->dev, ret, "failed to deassert 'rescal'\n"))
> > +             goto clk_disable_unprepare;
> >
> >       ret = brcm_phy_start(pcie);
> >       if (ret) {
> >               reset_control_rearm(pcie->rescal);
> > -             clk_disable_unprepare(pcie->clk);
> > -             return ret;
> > +             goto clk_disable_unprepare;
> >       }
> >
> >       ret = brcm_pcie_setup(pcie);
> > @@ -1654,10 +1649,8 @@ static int brcm_pcie_probe(struct platform_device *pdev)
> >       msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
> >       if (pci_msi_enabled() && msi_np == pcie->np) {
> >               ret = brcm_pcie_enable_msi(pcie);
> > -             if (ret) {
> > -                     dev_err(pcie->dev, "probe of internal MSI failed");
> > +             if (dev_err_probe(pcie->dev, ret, "probe of internal MSI failed"))
> >                       goto fail;
> > -             }
> >       }
> >
> >       bridge->ops = pcie->type == BCM7425 ? &brcm7425_pcie_ops : &brcm_pcie_ops;
> > @@ -1678,6 +1671,9 @@ static int brcm_pcie_probe(struct platform_device *pdev)
> >
> >  fail:
> >       __brcm_pcie_remove(pcie);
> > +clk_disable_unprepare:
> > +     clk_disable_unprepare(pcie->clk);
> > +
>
> TBH, this is not improving the code readability. __brcm_pcie_remove() used to
> free all the resources and now you just moved clk_disable_unprepare() out of it
> to save 2 lines in probe(). And you ended up calling clk_disable_unprepare()
> separately in brcm_pcie_remove().

Actually it saves more lines than that; the "swinit reset" commit adds
two more "goto clk_disable_unprepare" instances.

Nonetheless I will  make the change


Regards,
Jim Quinlan
Broadcom STB/CM




>
> So please remove the label and call clk_disable_unprepare() in the error path
> (just 2 instances) and continue to use __brcm_pcie_remove() to free all
> resources (I would've preferred to have separate error labels instead of calling
> __brcm_pcie_remove() though, but not this).
>
> - Mani
>
> --
> மணிவண்ணன் சதாசிவம்
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