[PATCH V2] PCI: qcom: Improve exception handling in qcom_pcie_probe().

[PATCH V2] PCI: qcom: Improve exception handling in qcom_pcie_probe().

[wu000273]

From: Qiushi Wu <wu000273@umn.edu>

This function contained improvable implementation details according to
exception handling.
1. pm_runtime_put() should be called after pm_runtime_get_sync() failed,
because the reference count will be increased despite of the failure.
Thus add the missed function call.
2. pm_runtime_disable() are called twice, after the call of phy_init() and
dw_pcie_host_init() failed. Thus remove redundant function calls.


Fixes: 6e5da6f7d824 ("PCI: qcom: Fix error handling in runtime PM support")
Co-developed-by: Markus Elfring <Markus.Elfring@web.de>
Signed-off-by: Markus Elfring <Markus.Elfring@web.de>
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
---
 V2: words adjustments and fix some typos 
 drivers/pci/controller/dwc/pcie-qcom.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 138e1a2d21cc..10393ab607bf 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -1340,8 +1340,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);
 	if (ret < 0) {
-		pm_runtime_disable(dev);
-		return ret;
+		goto err_pm_runtime_put;
 	}
 
 	pci->dev = dev;
@@ -1401,7 +1400,6 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 
 	ret = phy_init(pcie->phy);
 	if (ret) {
-		pm_runtime_disable(&pdev->dev);
 		goto err_pm_runtime_put;
 	}
 
@@ -1410,7 +1408,6 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	ret = dw_pcie_host_init(pp);
 	if (ret) {
 		dev_err(dev, "cannot initialize host\n");
-		pm_runtime_disable(&pdev->dev);
 		goto err_pm_runtime_put;
 	}
 
-- 
2.17.1

Re: [PATCH V2] PCI: qcom: Improve exception handling in qcom_pcie_probe()

[Markus Elfring]

> 1. pm_runtime_put() …
…
> 2. pm_runtime_disable() …

How do you think about to add blank lines for such enumeration items
and to indent the text below the numbers?


> Co-developed-by: Markus Elfring <Markus.Elfring@web.de>

Will our collaboration evolve in more ways besides patch review?

Regards,
Markus

Re: [PATCH V2] PCI: qcom: Improve exception handling in qcom_pcie_probe().

[Lorenzo Pieralisi]

On Tue, May 26, 2020 at 09:55:31PM -0500, wu000273@umn.edu wrote:
> From: Qiushi Wu <wu000273@umn.edu>
> 
> This function contained improvable implementation details according to
> exception handling.
> 1. pm_runtime_put() should be called after pm_runtime_get_sync() failed,
> because the reference count will be increased despite of the failure.
> Thus add the missed function call.
> 2. pm_runtime_disable() are called twice, after the call of phy_init() and
> dw_pcie_host_init() failed. Thus remove redundant function calls.

Can you send a patch fixing (2) based on my pci/runtime-pm branch:

git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git

pci/runtime-pm

Note that (1) is fixed by

https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/runtime-pm&id=cb52a40202420d3886b84ea13dba699c9da13eb0

> 
> Fixes: 6e5da6f7d824 ("PCI: qcom: Fix error handling in runtime PM support")
> Co-developed-by: Markus Elfring <Markus.Elfring@web.de>
> Signed-off-by: Markus Elfring <Markus.Elfring@web.de>
> Signed-off-by: Qiushi Wu <wu000273@umn.edu>
> ---
>  V2: words adjustments and fix some typos 
>  drivers/pci/controller/dwc/pcie-qcom.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 138e1a2d21cc..10393ab607bf 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -1340,8 +1340,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  	pm_runtime_enable(dev);
>  	ret = pm_runtime_get_sync(dev);
>  	if (ret < 0) {
> -		pm_runtime_disable(dev);
> -		return ret;
> +		goto err_pm_runtime_put;
>  	}
>  
>  	pci->dev = dev;
> @@ -1401,7 +1400,6 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  
>  	ret = phy_init(pcie->phy);
>  	if (ret) {
> -		pm_runtime_disable(&pdev->dev);
>  		goto err_pm_runtime_put;
>  	}
>  
> @@ -1410,7 +1408,6 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  	ret = dw_pcie_host_init(pp);
>  	if (ret) {
>  		dev_err(dev, "cannot initialize host\n");
> -		pm_runtime_disable(&pdev->dev);
>  		goto err_pm_runtime_put;
>  	}
>  
> -- 
> 2.17.1
>