[Linux-kernel-mentees] [PATCH v2 13/15] scsi: 3w-sas: use generic power management

[Vaibhav Gupta]

On Mon, Jul 20, 2020 at 07:04:26PM +0530, 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_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() and dev_get_drvdata() to get
> "struct pci_dev*" variable and drv data.
> 
> Compile-tested only.
> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
> ---
>  drivers/scsi/3w-sas.c | 31 ++++++++-----------------------
>  1 file changed, 8 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
> index dda6fa857709..efaba30b0ca8 100644
> --- a/drivers/scsi/3w-sas.c
> +++ b/drivers/scsi/3w-sas.c
> @@ -1756,11 +1756,10 @@ static void twl_remove(struct pci_dev *pdev)
>  	twl_device_extension_count--;
>  } /* End twl_remove() */
>  
> -#ifdef CONFIG_PM
>  /* This function is called on PCI suspend */
> -static int twl_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused twl_suspend(struct device *dev)
>  {
> -	struct Scsi_Host *host = pci_get_drvdata(pdev);
> +	struct Scsi_Host *host = dev_get_drvdata(dev);
>  	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
>  
>  	printk(KERN_WARNING "3w-sas: Suspending host %d.\n", tw_dev->host->host_no);
> @@ -1779,32 +1778,21 @@ static int twl_suspend(struct pci_dev *pdev, pm_message_t state)
>  	/* Clear doorbell interrupt */
>  	TWL_CLEAR_DB_INTERRUPT(tw_dev);
>  
> -	pci_save_state(pdev);
> -	pci_disable_device(pdev);
> -	pci_set_power_state(pdev, pci_choose_state(pdev, state));
> -
>  	return 0;
>  } /* End twl_suspend() */
>  
>  /* This function is called on PCI resume */
> -static int twl_resume(struct pci_dev *pdev)
> +static int __maybe_unused twl_resume(struct device *dev)
>  {
>  	int retval = 0;
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct Scsi_Host *host = pci_get_drvdata(pdev);
>  	TW_Device_Extension *tw_dev = (TW_Device_Extension *)host->hostdata;
>  
>  	printk(KERN_WARNING "3w-sas: Resuming host %d.\n", tw_dev->host->host_no);
> -	pci_set_power_state(pdev, PCI_D0);
> -	pci_enable_wake(pdev, PCI_D0, 0);
> -	pci_restore_state(pdev);
>  
> -	retval = pci_enable_device(pdev);
> -	if (retval) {
> -		TW_PRINTK(tw_dev->host, TW_DRIVER, 0x24, "Enable device failed during resume");
> -		return retval;
> -	}
> +	device_wakeup_disable(dev);
>  
> -	pci_set_master(pdev);
>  	pci_try_set_mwi(pdev);
>  
>  	retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
> @@ -1842,11 +1830,9 @@ static int twl_resume(struct pci_dev *pdev)
>  
>  out_disable_device:
>  	scsi_remove_host(host);
> -	pci_disable_device(pdev);
>  
>  	return retval;
>  } /* End twl_resume() */
> -#endif
>  
>  /* PCI Devices supported by this driver */
>  static struct pci_device_id twl_pci_tbl[] = {
> @@ -1855,16 +1841,15 @@ static struct pci_device_id twl_pci_tbl[] = {
>  };
>  MODULE_DEVICE_TABLE(pci, twl_pci_tbl);
>  
> +static SIMPLE_DEV_PM_OPS(twl_pm_ops, twl_suspend, twl_resume);
> +
>  /* pci_driver initializer */
>  static struct pci_driver twl_driver = {
>  	.name		= "3w-sas",
>  	.id_table	= twl_pci_tbl,
>  	.probe		= twl_probe,
>  	.remove		= twl_remove,
> -#ifdef CONFIG_PM
> -	.suspend	= twl_suspend,
> -	.resume		= twl_resume,
> -#endif
> +	.driver.pm	= &twl_pm_ops,
>  	.shutdown	= twl_shutdown
>  };
>  
> -- 
> 2.27.0
> 
.