Re: [PATCH v3] PCI: armada8k: change to use devm_clk_get_enabled() helper

[Wu Bo]

On 2024/8/27 14:44, Anand Moon wrote:
> Hi Wu Bo,
>
> On Tue, 27 Aug 2024 at 07:55, Wu Bo <bo.wu@xxxxxxxx> wrote:
> > Use devm_clk_get_enabled() instead of devm_clk_get() to make the code
> > cleaner and avoid calling clk_disable_unprepare()
> >
> > Signed-off-by: Wu Bo <bo.wu@xxxxxxxx>
> > ---
> >   drivers/pci/controller/dwc/pcie-armada8k.c | 36 ++++++++--------------
> >   1 file changed, 13 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-armada8k.c b/drivers/pci/controller/dwc/pcie-armada8k.c
> > index b5c599ccaacf..e7ef6c2641b8 100644
> > --- a/drivers/pci/controller/dwc/pcie-armada8k.c
> > +++ b/drivers/pci/controller/dwc/pcie-armada8k.c
> > @@ -284,23 +284,17 @@ static int armada8k_pcie_probe(struct platform_device *pdev)
> >
> >          pcie->pci = pci;
> >
> > -       pcie->clk = devm_clk_get(dev, NULL);
> > +       pcie->clk = devm_clk_get_enabled(dev, NULL);
> >          if (IS_ERR(pcie->clk))
> > -               return PTR_ERR(pcie->clk);
> > -
> > -       ret = clk_prepare_enable(pcie->clk);
> > -       if (ret)
> > -               return ret;
> > -
> > -       pcie->clk_reg = devm_clk_get(dev, "reg");
> > -       if (pcie->clk_reg == ERR_PTR(-EPROBE_DEFER)) {
> > -               ret = -EPROBE_DEFER;
> > -               goto fail;
> > -       }

I don't know much about this device. But from the code here, its 
previous logic is that the function will only return when the error code 
is EPROBE_DEFER, and other errors will continue to execute.

So I followed the previous logic, is it correct？

> > -       if (!IS_ERR(pcie->clk_reg)) {
> > -               ret = clk_prepare_enable(pcie->clk_reg);
> > -               if (ret)
> > -                       goto fail_clkreg;
> > +               return dev_err_probe(dev, PTR_ERR(pcie->clk),
> > +                               "could not enable clk\n");
> > +
> > +       pcie->clk_reg = devm_clk_get_enabled(dev, "reg");
> > +       if (IS_ERR(pcie->clk_reg)) {
> > +               ret = dev_err_probe(dev, PTR_ERR(pcie->clk_reg),
> > +                               "could not enable reg clk\n");
> > +               if (ret == -EPROBE_DEFER)
> > +                       goto out;
> You can drop this check as dev_err_probe handle this inside
> It will defer the enabling of clock.
> >          }
> >
> >          /* Get the dw-pcie unit configuration/control registers base. */
> > @@ -308,12 +302,12 @@ static int armada8k_pcie_probe(struct platform_device *pdev)
> >          pci->dbi_base = devm_pci_remap_cfg_resource(dev, base);
> >          if (IS_ERR(pci->dbi_base)) {
> >                  ret = PTR_ERR(pci->dbi_base);
> > -               goto fail_clkreg;
> > +               goto out;
> >          }
> >
> >          ret = armada8k_pcie_setup_phys(pcie);
> >          if (ret)
> > -               goto fail_clkreg;
> > +               goto out;
> >
> >          platform_set_drvdata(pdev, pcie);
> >
> > @@ -325,11 +319,7 @@ static int armada8k_pcie_probe(struct platform_device *pdev)
> >
> >   disable_phy:
> >          armada8k_pcie_disable_phys(pcie);
> > -fail_clkreg:
> > -       clk_disable_unprepare(pcie->clk_reg);
> > -fail:
> > -       clk_disable_unprepare(pcie->clk);
> > -
> > +out:
> >          return ret;
> >   }
> Thanks
> -Anand
> > --
> > 2.25.1