Re: [Linux-kernel-mentees] [PATCH v2 05/15] scsi: arcmsr: use generic power management

[Vaibhav Gupta <vaibhavgupta40@gmail.com>]

On Mon, Jul 20, 2020 at 07:04:18PM +0530, Vaibhav Gupta wrote:
> With legacy PM hooks, it was the responsibility of a driver to manage PCI
> states and also the device's power state. The generic approach is to let
> the PCI core handle the work.
> 
> PCI core passes "struct device*" as an argument to the .suspend() and
> .resume() callbacks.
> 
> Driver was also using PCI helper functions like pci_save/restore_state(),
> pci_disable/enable_device(), pci_set_power_state() and pci_enable_wake().
> They should not be invoked by the driver.
> 
> Compile-tested only.
> 
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
> ---
>  drivers/scsi/arcmsr/arcmsr_hba.c | 35 ++++++++++++--------------------
>  1 file changed, 13 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
> index 30914c8f29cc..7e098ddcc4f5 100644
> --- a/drivers/scsi/arcmsr/arcmsr_hba.c
> +++ b/drivers/scsi/arcmsr/arcmsr_hba.c
> @@ -113,8 +113,8 @@ static int arcmsr_bios_param(struct scsi_device *sdev,
>  static int arcmsr_queue_command(struct Scsi_Host *h, struct scsi_cmnd *cmd);
>  static int arcmsr_probe(struct pci_dev *pdev,
>  				const struct pci_device_id *id);
> -static int arcmsr_suspend(struct pci_dev *pdev, pm_message_t state);
> -static int arcmsr_resume(struct pci_dev *pdev);
> +static int __maybe_unused arcmsr_suspend(struct device *dev);
> +static int __maybe_unused arcmsr_resume(struct device *dev);
>  static void arcmsr_remove(struct pci_dev *pdev);
>  static void arcmsr_shutdown(struct pci_dev *pdev);
>  static void arcmsr_iop_init(struct AdapterControlBlock *acb);
> @@ -213,13 +213,14 @@ static struct pci_device_id arcmsr_device_id_table[] = {
>  };
>  MODULE_DEVICE_TABLE(pci, arcmsr_device_id_table);
>  
> +static SIMPLE_DEV_PM_OPS(arcmsr_pm_ops, arcmsr_suspend, arcmsr_resume);
> +
>  static struct pci_driver arcmsr_pci_driver = {
>  	.name			= "arcmsr",
>  	.id_table		= arcmsr_device_id_table,
>  	.probe			= arcmsr_probe,
>  	.remove			= arcmsr_remove,
> -	.suspend		= arcmsr_suspend,
> -	.resume			= arcmsr_resume,
> +	.driver.pm		= &arcmsr_pm_ops,
>  	.shutdown		= arcmsr_shutdown,
>  };
>  /*
> @@ -1065,14 +1066,14 @@ static void arcmsr_free_irq(struct pci_dev *pdev,
>  	pci_free_irq_vectors(pdev);
>  }
>  
> -static int arcmsr_suspend(struct pci_dev *pdev, pm_message_t state)
> +static int __maybe_unused arcmsr_suspend(struct device *dev)
>  {
> -	uint32_t intmask_org;
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct Scsi_Host *host = pci_get_drvdata(pdev);
>  	struct AdapterControlBlock *acb =
>  		(struct AdapterControlBlock *)host->hostdata;
>  
> -	intmask_org = arcmsr_disable_outbound_ints(acb);
> +	arcmsr_disable_outbound_ints(acb);
>  	arcmsr_free_irq(pdev, acb);
>  	del_timer_sync(&acb->eternal_timer);
>  	if (set_date_time)
> @@ -1080,29 +1081,21 @@ static int arcmsr_suspend(struct pci_dev *pdev, pm_message_t state)
>  	flush_work(&acb->arcmsr_do_message_isr_bh);
>  	arcmsr_stop_adapter_bgrb(acb);
>  	arcmsr_flush_adapter_cache(acb);
> -	pci_set_drvdata(pdev, host);
> -	pci_save_state(pdev);
> -	pci_disable_device(pdev);
> -	pci_set_power_state(pdev, pci_choose_state(pdev, state));
>  	return 0;
>  }
>  
> -static int arcmsr_resume(struct pci_dev *pdev)
> +static int __maybe_unused arcmsr_resume(struct device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev);
>  	struct Scsi_Host *host = pci_get_drvdata(pdev);
>  	struct AdapterControlBlock *acb =
>  		(struct AdapterControlBlock *)host->hostdata;
>  
> -	pci_set_power_state(pdev, PCI_D0);
> -	pci_enable_wake(pdev, PCI_D0, 0);
> -	pci_restore_state(pdev);
> -	if (pci_enable_device(pdev)) {
> -		pr_warn("%s: pci_enable_device error\n", __func__);
> -		return -ENODEV;
> -	}
> +	device_wakeup_disable(dev);
> +
>  	if (arcmsr_set_dma_mask(acb))
>  		goto controller_unregister;
> -	pci_set_master(pdev);
> +
>  	if (arcmsr_request_irq(pdev, acb) == FAILED)
>  		goto controller_stop;
>  	switch (acb->adapter_type) {
> @@ -1137,9 +1130,7 @@ static int arcmsr_resume(struct pci_dev *pdev)
>  	scsi_remove_host(host);
>  	arcmsr_free_ccb_pool(acb);
>  	arcmsr_unmap_pciregion(acb);
> -	pci_release_regions(pdev);
>  	scsi_host_put(host);
> -	pci_disable_device(pdev);
>  	return -ENODEV;
>  }
>  
> -- 
> 2.27.0
> 
.
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