[Linux-kernel-mentees] [PATCH v3 3/3] skd: use generic power management

[Damien Le Moal]

On 2020/07/22 17:35, Vaibhav Gupta wrote:
> Drivers using legacy power management .suspen()/.resume() callbacks
> have to manage PCI states and device's PM states themselves. They also
> need to take care of standard configuration registers.
> 
> Switch to generic power management framework using a single
> "struct dev_pm_ops" variable to take the unnecessary load from the driver.
> This also avoids the need for the driver to directly call most of the PCI
> helper functions and device power state control functions, as through
> the generic framework PCI Core takes care of the necessary operations,
> and drivers are required to do only device-specific jobs.
> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
> ---
>  drivers/block/skd_main.c | 30 ++++++++----------------------
>  1 file changed, 8 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> index 51569c199a6c..7f2d42900b38 100644
> --- a/drivers/block/skd_main.c
> +++ b/drivers/block/skd_main.c
> @@ -3315,10 +3315,11 @@ 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);
>  
>  	skdev = pci_get_drvdata(pdev);
>  	if (!skdev) {
> @@ -3337,18 +3338,15 @@ 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;
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  
>  	skdev = pci_get_drvdata(pdev);
>  	if (!skdev) {
> @@ -3356,16 +3354,8 @@ static int skd_pci_resume(struct pci_dev *pdev)
>  		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 +3364,6 @@ 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 +3416,6 @@ 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 +3435,14 @@ 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,
>  };
>  
> 

Tested-by: Damien Le Moal <damien.lemoal at wdc.com>
Acked-by: Damien Le Moal <damien.lemoal at wdc.com>


-- 
Damien Le Moal
Western Digital Research