1. Patchew
  2. linux
  3. View series

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

Wu Bo posted 1 patch 1 year, 3 months ago 
drivers/pci/controller/dwc/pcie-armada8k.c | 36 ++++++++--------------
1 file changed, 13 insertions(+), 23 deletions(-)
[PATCH v3] PCI: armada8k: change to use devm_clk_get_enabled() helper
Posted by Wu Bo 1 year, 3 months ago 
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@vivo.com>
---
 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;
-	}
-	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;
 	}
 
 	/* 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;
 }
 
-- 
2.25.1
Re: [PATCH v3] PCI: armada8k: change to use devm_clk_get_enabled() helper
Posted by Anand Moon 1 year, 3 months ago 
Hi Wu Bo,

On Tue, 27 Aug 2024 at 07:55, Wu Bo <bo.wu@vivo.com> 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@vivo.com>
> ---
>  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;
> -       }
> -       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
>
>
Re: [PATCH v3] PCI: armada8k: change to use devm_clk_get_enabled() helper
Posted by Wu Bo 1 year, 3 months ago 
On 2024/8/27 14:44, Anand Moon wrote:
> Hi Wu Bo,
>
> On Tue, 27 Aug 2024 at 07:55, Wu Bo <bo.wu@vivo.com> 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@vivo.com>
>> ---
>>   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
>>
>>
Re: [PATCH v3] PCI: armada8k: change to use devm_clk_get_enabled() helper
Posted by Anand Moon 1 year, 3 months ago 
Hi Wu Bo,

On Sat, 31 Aug 2024 at 05:36, Wu Bo <wubo.oduw@gmail.com> wrote:
>
> On 2024/8/27 14:44, Anand Moon wrote:
> > Hi Wu Bo,
> >
> > On Tue, 27 Aug 2024 at 07:55, Wu Bo <bo.wu@vivo.com> 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@vivo.com>
> >> ---
> >>   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？

We probably get -EPROBE_DEFER since the clk is not getting enabled during probe.
and we defer the initialization by returning the error. using
dev_err_probe function.
.
We don't need to recheck for EPROBE_DEFER, again it's handled in
dev_err_probe see below.

[1] https://elixir.bootlin.com/linux/v6.10.7/source/drivers/base/core.c#L5018

Thanks
-Anand
>
> >> -       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
> >>
> >>

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.