[Linux-kernel-mentees] [PATCH v1 3/3] skd: use generic power management

Vaibhav Gupta vaibhavgupta40 at gmail.com
Mon Jul 20 13:16:27 UTC 2020


On Mon, Jul 20, 2020 at 12:52:14PM +0000, Damien Le Moal wrote:
> On 2020/07/17 17:10, 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_request/release_regions(), 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() to get "struct pci_dev*" variable.
> > 
> > Compile-tested only.
> 
> I do not think this belongs into the commit message. This was mentioned in the
> cover letter.
>
The messages in cover letter and commit message are bit similar. But the commit
message has patch specific changes mentioned in it.
> > 
> > Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
> > ---
> >  drivers/block/skd_main.c | 36 ++++++++++--------------------------
> >  1 file changed, 10 insertions(+), 26 deletions(-)
> > 
> > diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> > index 51569c199a6c..d8d1042e7338 100644
> > --- a/drivers/block/skd_main.c
> > +++ b/drivers/block/skd_main.c
> > @@ -3315,12 +3315,12 @@ 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);
> > +	struct skd_device *skdev = pci_get_drvdata(pdev);
> 
> You can just add the pdev declaration here. The other 2 changes are not needed.
> 
Okay.
> >  
> > -	skdev = pci_get_drvdata(pdev);
> 
> You can keep this as is.
> 
> >  	if (!skdev) {
> >  		dev_err(&pdev->dev, "no device data for PCI\n");
> >  		return -EIO;
> > @@ -3337,35 +3337,23 @@ 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;
> >  
> > -	skdev = pci_get_drvdata(pdev);
> 
> Same comment as above. Keep these as is and add only pdev declaration.
> 
Okay.
Sending v2 with suggested changes.

--Vaibhav Gupta
> > +	struct pci_dev *pdev = to_pci_dev(dev);
> > +	struct skd_device *skdev = pci_get_drvdata(pdev);
> >  	if (!skdev) {
> >  		dev_err(&pdev->dev, "no device data for PCI\n");
> >  		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 +3362,6 @@ 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 +3414,6 @@ 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 +3433,14 @@ 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,
> >  };
> >  
> > 
> 
> 
> -- 
> Damien Le Moal
> Western Digital Research


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