Re: [PATCH v1 3/3] pwm: dwc: use to_pci_dev() helper

Uwe Kleine-König
2024-01-28T16:55:10Z

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Hello,

On Sun, Jan 28, 2024 at 04:46:48PM +0200, Andy Shevchenko wrote:
> On Mon, Jan 22, 2024 at 08:32:38AM +0530, Raag Jadav wrote:
> > Use to_pci_dev() helper to get pci device reference.
>
> PCI
>
> ...
>
> > static int dwc_pwm_suspend(struct device *dev)
> > {
> > - struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > struct dwc_pwm *dwc = pci_get_drvdata(pdev);
> > int i;
> >
> > @@ -120,7 +120,7 @@ static int dwc_pwm_suspend(struct device *dev)
> >
> > static int dwc_pwm_resume(struct device *dev)
> > {
> > - struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
> > + struct pci_dev *pdev = to_pci_dev(dev);
> > struct dwc_pwm *dwc = pci_get_drvdata(pdev);
> > int i;
>
> I don't see how pdev is being used. That said, why dev_get_drvdata() is not
> suffice?

I would even consider using dev_get_drvdata() a nice cleanup given that
pci_get_drvdata() works because dwc_pwm_alloc() called dev_set_drvdata()
(and not pci_set_drvdata()).

Not so long ago (i.e. before commit a357d1493f0c ("pwm: dwc: Move memory
allocation to own function")) the dwc driver was pci only and used
pci_set_drvdata(). Then the upside of first converting the struct device
to a struct pci_dev was not to hard code knowledge about the
implementation of pci_[gs]et_drvdata().

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |

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