Re: [PATCH v2 10/15] scsi: pm_8001: use generic power management

[Vaibhav Gupta <vaibhavgupta40@gmail.com>]

On Mon, Jul 20, 2020 at 07:04:23PM +0530, Vaibhav Gupta wrote:
> With legacy PM, drivers themselves were responsible for managing the
> device's power states and takes care of register states.
> 
> After upgrading to the generic structure, PCI core will take care of
> required tasks and drivers should do only device-specific operations.
> 
> The driver was calling pci_save/restore_state(), pci_choose_state(),
> pci_enable/disable_device() and pci_set_power_state() which is no more
> needed.
> 
> Compile-tested only.
> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> ---
>  drivers/scsi/pm8001/pm8001_init.c | 46 ++++++++++++-------------------
>  1 file changed, 17 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index 9e99262a2b9d..d7d664b87720 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -1178,23 +1178,21 @@ static void pm8001_pci_remove(struct pci_dev *pdev)
>  
>  /**
>   * pm8001_pci_suspend - power management suspend main entry point
> - * @pdev: PCI device struct
> - * @state: PM state change to (usually PCI_D3)
> + * @dev: Device struct
>   *
>   * Returns 0 success, anything else error.
>   */
> -static int pm8001_pci_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused pm8001_pci_suspend(struct device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct sas_ha_struct *sha = pci_get_drvdata(pdev);
> -	struct pm8001_hba_info *pm8001_ha;
> +	struct pm8001_hba_info *pm8001_ha = sha->lldd_ha;
>  	int  i, j;
> -	u32 device_state;
> -	pm8001_ha = sha->lldd_ha;
>  	sas_suspend_ha(sha);
>  	flush_workqueue(pm8001_wq);
>  	scsi_block_requests(pm8001_ha->shost);
>  	if (!pdev->pm_cap) {
> -		dev_err(&pdev->dev, " PCI PM not supported\n");
> +		dev_err(dev, " PCI PM not supported\n");
>  		return -ENODEV;
>  	}
>  	PM8001_CHIP_DISP->interrupt_disable(pm8001_ha, 0xFF);
> @@ -1217,24 +1215,21 @@ static int pm8001_pci_suspend(struct pci_dev *pdev, pm_message_t state)
>  		for (j = 0; j < PM8001_MAX_MSIX_VEC; j++)
>  			tasklet_kill(&pm8001_ha->tasklet[j]);
>  #endif
> -	device_state = pci_choose_state(pdev, state);
>  	pm8001_printk("pdev=0x%p, slot=%s, entering "
> -		      "operating state [D%d]\n", pdev,
> -		      pm8001_ha->name, device_state);
> -	pci_save_state(pdev);
> -	pci_disable_device(pdev);
> -	pci_set_power_state(pdev, device_state);
> +		      "suspended state\n", pdev,
> +		      pm8001_ha->name);
>  	return 0;
>  }
>  
>  /**
>   * pm8001_pci_resume - power management resume main entry point
> - * @pdev: PCI device struct
> + * @dev: Device struct
>   *
>   * Returns 0 success, anything else error.
>   */
> -static int pm8001_pci_resume(struct pci_dev *pdev)
> +static int __maybe_unused pm8001_pci_resume(struct device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct sas_ha_struct *sha = pci_get_drvdata(pdev);
>  	struct pm8001_hba_info *pm8001_ha;
>  	int rc;
> @@ -1247,17 +1242,8 @@ static int pm8001_pci_resume(struct pci_dev *pdev)
>  	pm8001_printk("pdev=0x%p, slot=%s, resuming from previous "
>  		"operating state [D%d]\n", pdev, pm8001_ha->name, device_state);
>  
> -	pci_set_power_state(pdev, PCI_D0);
> -	pci_enable_wake(pdev, PCI_D0, 0);
> -	pci_restore_state(pdev);
> -	rc = pci_enable_device(pdev);
> -	if (rc) {
> -		pm8001_printk("slot=%s Enable device failed during resume\n",
> -			      pm8001_ha->name);
> -		goto err_out_enable;
> -	}
> +	device_wakeup_disable(dev);
>  
> -	pci_set_master(pdev);
>  	rc = pci_go_44(pdev);
>  	if (rc)
>  		goto err_out_disable;
> @@ -1318,8 +1304,7 @@ static int pm8001_pci_resume(struct pci_dev *pdev)
>  
>  err_out_disable:
>  	scsi_remove_host(pm8001_ha->shost);
> -	pci_disable_device(pdev);
> -err_out_enable:
> +
>  	return rc;
>  }
>  
> @@ -1402,13 +1387,16 @@ static struct pci_device_id pm8001_pci_table[] = {
>  	{} /* terminate list */
>  };
>  
> +static SIMPLE_DEV_PM_OPS(pm8001_pci_pm_ops,
> +			 pm8001_pci_suspend,
> +			 pm8001_pci_resume);
> +
>  static struct pci_driver pm8001_pci_driver = {
>  	.name		= DRV_NAME,
>  	.id_table	= pm8001_pci_table,
>  	.probe		= pm8001_pci_probe,
>  	.remove		= pm8001_pci_remove,
> -	.suspend	= pm8001_pci_suspend,
> -	.resume		= pm8001_pci_resume,
> +	.driver.pm	= &pm8001_pci_pm_ops,
>  };
>  
>  /**
> -- 
> 2.27.0
> 
.