linux-kernel - Re: [PATCH v2 1/2] platform/x86: amd-pmc: Store the pci_dev instance inside struct amd_pmc

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Message-ID: <f903b9d5-0477-1618-6596-b6039b56a5af@redhat.com>
Date:   Thu, 21 Oct 2021 20:18:33 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Sanket Goswami <Sanket.Goswami@....com>, Shyam-sundar.S-k@....com,
        mgross@...ux.intel.com
Cc:     platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] platform/x86: amd-pmc: Store the pci_dev instance
 inside struct amd_pmc_dev

Hi,

On 10/21/21 11:29, Sanket Goswami wrote:
> Store the root port information in amd_pmc_probe() so that the
> information can be used across multiple routines.
> 
> Signed-off-by: Sanket Goswami <Sanket.Goswami@....com>
> ---
> Changes in v2:
> - Store the rdev info in amd_pmc_probe() as suggested by Hans.

Thank you, but there are still some issues, see below.


>  drivers/platform/x86/amd-pmc.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
> index 55f14bdfdbfd..502f37eaba1f 100644
> --- a/drivers/platform/x86/amd-pmc.c
> +++ b/drivers/platform/x86/amd-pmc.c
> @@ -119,6 +119,7 @@ struct amd_pmc_dev {
>  	u16 minor;
>  	u16 rev;
>  	struct device *dev;
> +	struct pci_dev *rdev;
>  	struct mutex lock; /* generic mutex lock */
>  #if IS_ENABLED(CONFIG_DEBUG_FS)
>  	struct dentry *dbgfs_dir;
> @@ -482,6 +483,7 @@ static int amd_pmc_probe(struct platform_device *pdev)
>  		return -ENODEV;
>  	}
>  
> +	dev->rdev = rdev;
>  	dev->cpu_id = rdev->device;
>  	err = pci_write_config_dword(rdev, AMD_PMC_SMU_INDEX_ADDRESS, AMD_PMC_BASE_ADDR_LO);
>  	if (err) {
> @@ -512,7 +514,6 @@ static int amd_pmc_probe(struct platform_device *pdev)
>  	}
>  
>  	base_addr_hi = val & AMD_PMC_BASE_ADDR_LO_MASK;
> -	pci_dev_put(dev->rdev);

The current code here actually reads:

	pci_dev_put(rdev);

Note (rdev) not (dev->rdev). I don't know what you based this on, this is weird.

Also there are a bunch of error-exits from amd_pmc_probe() which not all
need a "pci_dev_put(rdev)" added to them before there "return ERROR;"
statement.

It would be best to add:

err_pci_dev_put:
	pci_dev_put(rdev);
	return err;

Add the end off the function (after the return 0;) and replace all
"return FOO" error-exits with:

		err = <FOO>;
		goto err_pci_dev_put;
	}



Regards,

Hans




>  	base_addr = ((u64)base_addr_hi << 32 | base_addr_lo);
>  
>  	dev->regbase = devm_ioremap(dev->dev, base_addr + AMD_PMC_BASE_ADDR_OFFSET,
> @@ -546,6 +547,7 @@ static int amd_pmc_remove(struct platform_device *pdev)
>  	struct amd_pmc_dev *dev = platform_get_drvdata(pdev);
>  
>  	amd_pmc_dbgfs_unregister(dev);
> +	pci_dev_put(dev->rdev);
>  	mutex_destroy(&dev->lock);
>  	return 0;
>  }
>