Re: [Linux-kernel-mentees] [PATCH v1 3/3] skd: use generic power management

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2020/07/17 17:10, Vaibhav Gupta wrote:
> Drivers using legacy PM have to manage PCI states and device's PM states
> themselves. They also need to take care of configuration registers.
> 
> With improved and powerful support of generic PM, PCI Core takes care of
> above mentioned, device-independent, jobs.
> 
> This driver makes use of PCI helper functions like
> pci_save/restore_state(), pci_enable/disable_device(),
> pci_request/release_regions(), pci_set_power_state() and
> pci_set_master() to do required operations. In generic mode, they are no
> longer needed.
> 
> Change function parameter in both .suspend() and .resume() to
> "struct device*" type. Use to_pci_dev() to get "struct pci_dev*" variable.
> 
> Compile-tested only.

I do not think this belongs into the commit message. This was mentioned in the
cover letter.

> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> ---
>  drivers/block/skd_main.c | 36 ++++++++++--------------------------
>  1 file changed, 10 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> index 51569c199a6c..d8d1042e7338 100644
> --- a/drivers/block/skd_main.c
> +++ b/drivers/block/skd_main.c
> @@ -3315,12 +3315,12 @@ static void skd_pci_remove(struct pci_dev *pdev)
>  	return;
>  }
>  
> -static int skd_pci_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused skd_pci_suspend(struct device *dev)
>  {
>  	int i;
> -	struct skd_device *skdev;
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct skd_device *skdev = pci_get_drvdata(pdev);

You can just add the pdev declaration here. The other 2 changes are not needed.

>  
> -	skdev = pci_get_drvdata(pdev);

You can keep this as is.

>  	if (!skdev) {
>  		dev_err(&pdev->dev, "no device data for PCI\n");
>  		return -EIO;
> @@ -3337,35 +3337,23 @@ static int skd_pci_suspend(struct pci_dev *pdev, pm_message_t state)
>  	if (skdev->pcie_error_reporting_is_enabled)
>  		pci_disable_pcie_error_reporting(pdev);
>  
> -	pci_release_regions(pdev);
> -	pci_save_state(pdev);
> -	pci_disable_device(pdev);
> -	pci_set_power_state(pdev, pci_choose_state(pdev, state));
>  	return 0;
>  }
>  
> -static int skd_pci_resume(struct pci_dev *pdev)
> +static int __maybe_unused skd_pci_resume(struct device *dev)
>  {
>  	int i;
>  	int rc = 0;
> -	struct skd_device *skdev;
>  
> -	skdev = pci_get_drvdata(pdev);

Same comment as above. Keep these as is and add only pdev declaration.

> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	struct skd_device *skdev = pci_get_drvdata(pdev);
>  	if (!skdev) {
>  		dev_err(&pdev->dev, "no device data for PCI\n");
>  		return -1;
>  	}
>  
> -	pci_set_power_state(pdev, PCI_D0);
> -	pci_enable_wake(pdev, PCI_D0, 0);
> -	pci_restore_state(pdev);
> +	device_wakeup_disable(dev);
>  
> -	rc = pci_enable_device(pdev);
> -	if (rc)
> -		return rc;
> -	rc = pci_request_regions(pdev, DRV_NAME);
> -	if (rc)
> -		goto err_out;
>  	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>  	if (rc)
>  		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> @@ -3374,7 +3362,6 @@ static int skd_pci_resume(struct pci_dev *pdev)
>  		goto err_out_regions;
>  	}
>  
> -	pci_set_master(pdev);
>  	rc = pci_enable_pcie_error_reporting(pdev);
>  	if (rc) {
>  		dev_err(&pdev->dev,
> @@ -3427,10 +3414,6 @@ static int skd_pci_resume(struct pci_dev *pdev)
>  		pci_disable_pcie_error_reporting(pdev);
>  
>  err_out_regions:
> -	pci_release_regions(pdev);
> -
> -err_out:
> -	pci_disable_device(pdev);
>  	return rc;
>  }
>  
> @@ -3450,13 +3433,14 @@ static void skd_pci_shutdown(struct pci_dev *pdev)
>  	skd_stop_device(skdev);
>  }
>  
> +static SIMPLE_DEV_PM_OPS(skd_pci_pm_ops, skd_pci_suspend, skd_pci_resume);
> +
>  static struct pci_driver skd_driver = {
>  	.name		= DRV_NAME,
>  	.id_table	= skd_pci_tbl,
>  	.probe		= skd_pci_probe,
>  	.remove		= skd_pci_remove,
> -	.suspend	= skd_pci_suspend,
> -	.resume		= skd_pci_resume,
> +	.driver.pm	= &skd_pci_pm_ops,
>  	.shutdown	= skd_pci_shutdown,
>  };
>  
> 


-- 
Damien Le Moal
Western Digital Research
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