Re: [Linux-kernel-mentees] [PATCH v2 08/15] scsi: mpt3sas_scsih: use generic power management

[Vaibhav Gupta <vaibhavgupta40@gmail.com>]

On Mon, Jul 20, 2020 at 07:04:21PM +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/mpt3sas/mpt3sas_scsih.c | 36 +++++++++++-----------------
>  1 file changed, 14 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> index 08fc4b381056..f3c6e68b2921 100644
> --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
> @@ -10829,44 +10829,40 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	return rv;
>  }
>  
> -#ifdef CONFIG_PM
>  /**
>   * scsih_suspend - power management suspend main entry point
> - * @pdev: PCI device struct
> - * @state: PM state change to (usually PCI_D3)
> + * @dev: Device struct
>   *
>   * Return: 0 success, anything else error.
>   */
> -static int
> -scsih_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused
> +scsih_suspend(struct device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct Scsi_Host *shost = pci_get_drvdata(pdev);
>  	struct MPT3SAS_ADAPTER *ioc = shost_priv(shost);
> -	pci_power_t device_state;
>  
>  	mpt3sas_base_stop_watchdog(ioc);
>  	flush_scheduled_work();
>  	scsi_block_requests(shost);
>  	_scsih_nvme_shutdown(ioc);
> -	device_state = pci_choose_state(pdev, state);
> -	ioc_info(ioc, "pdev=0x%p, slot=%s, entering operating state [D%d]\n",
> -		 pdev, pci_name(pdev), device_state);
> +	ioc_info(ioc, "pdev=0x%p, slot=%s, entering suspended state\n",
> +		 pdev, pci_name(pdev));
>  
> -	pci_save_state(pdev);
>  	mpt3sas_base_free_resources(ioc);
> -	pci_set_power_state(pdev, device_state);
>  	return 0;
>  }
>  
>  /**
>   * scsih_resume - power management resume main entry point
> - * @pdev: PCI device struct
> + * @dev: Device struct
>   *
>   * Return: 0 success, anything else error.
>   */
> -static int
> -scsih_resume(struct pci_dev *pdev)
> +static int __maybe_unused
> +scsih_resume(struct device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct Scsi_Host *shost = pci_get_drvdata(pdev);
>  	struct MPT3SAS_ADAPTER *ioc = shost_priv(shost);
>  	pci_power_t device_state = pdev->current_state;
> @@ -10875,9 +10871,7 @@ scsih_resume(struct pci_dev *pdev)
>  	ioc_info(ioc, "pdev=0x%p, slot=%s, previous operating state [D%d]\n",
>  		 pdev, pci_name(pdev), device_state);
>  
> -	pci_set_power_state(pdev, PCI_D0);
> -	pci_enable_wake(pdev, PCI_D0, 0);
> -	pci_restore_state(pdev);
> +	device_wakeup_disable(dev);
>  	ioc->pdev = pdev;
>  	r = mpt3sas_base_map_resources(ioc);
>  	if (r)
> @@ -10888,7 +10882,6 @@ scsih_resume(struct pci_dev *pdev)
>  	mpt3sas_base_start_watchdog(ioc);
>  	return 0;
>  }
> -#endif /* CONFIG_PM */
>  
>  /**
>   * scsih_pci_error_detected - Called when a PCI error is detected.
> @@ -11162,6 +11155,8 @@ static struct pci_error_handlers _mpt3sas_err_handler = {
>  	.resume		= scsih_pci_resume,
>  };
>  
> +static SIMPLE_DEV_PM_OPS(scsih_pm_ops, scsih_suspend, scsih_resume);
> +
>  static struct pci_driver mpt3sas_driver = {
>  	.name		= MPT3SAS_DRIVER_NAME,
>  	.id_table	= mpt3sas_pci_table,
> @@ -11169,10 +11164,7 @@ static struct pci_driver mpt3sas_driver = {
>  	.remove		= scsih_remove,
>  	.shutdown	= scsih_shutdown,
>  	.err_handler	= &_mpt3sas_err_handler,
> -#ifdef CONFIG_PM
> -	.suspend	= scsih_suspend,
> -	.resume		= scsih_resume,
> -#endif
> +	.driver.pm	= &scsih_pm_ops,
>  };
>  
>  /**
> -- 
> 2.27.0
> 
.
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