[Linux-kernel-mentees] [PATCH v1] [media] saa7134: use generic power management

[Vaibhav Gupta]

On Mon, Jun 22, 2020 at 5:36 PM Vaibhav Gupta <vaibhavgupta40 at gmail.com> wrote:
>
> With the support of generic PM callbacks, drivers no longer need to use
> legacy .suspend() and .resume() in which they had to maintain PCI states
> changes and device's power state themselves. The required operations are
> done by PCI core.
>
> Compile-tested only.
>
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
> ---
>  drivers/media/pci/saa7134/saa7134-core.c | 25 ++++++++----------------
>  1 file changed, 8 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
> index e4623ed2f831..eb01109d4f98 100644
> --- a/drivers/media/pci/saa7134/saa7134-core.c
> +++ b/drivers/media/pci/saa7134/saa7134-core.c
> @@ -1370,10 +1370,8 @@ static void saa7134_finidev(struct pci_dev *pci_dev)
>         kfree(dev);
>  }
>
> -#ifdef CONFIG_PM
> -
>  /* resends a current buffer in queue after resume */
> -static int saa7134_buffer_requeue(struct saa7134_dev *dev,
> +static int __maybe_unused saa7134_buffer_requeue(struct saa7134_dev *dev,
>                                   struct saa7134_dmaqueue *q)
>  {
>         struct saa7134_buf *buf, *next;
> @@ -1397,8 +1395,9 @@ static int saa7134_buffer_requeue(struct saa7134_dev *dev,
>         return 0;
>  }
>
> -static int saa7134_suspend(struct pci_dev *pci_dev , pm_message_t state)
> +static int __maybe_unused saa7134_suspend(struct device *dev_d)
>  {
> +       struct pci_dev *pci_dev = to_pci_dev(dev_d);
>         struct v4l2_device *v4l2_dev = pci_get_drvdata(pci_dev);
>         struct saa7134_dev *dev = container_of(v4l2_dev, struct saa7134_dev, v4l2_dev);
>
> @@ -1428,21 +1427,15 @@ static int saa7134_suspend(struct pci_dev *pci_dev , pm_message_t state)
>         if (dev->remote && dev->remote->dev->users)
>                 saa7134_ir_close(dev->remote->dev);
>
> -       pci_save_state(pci_dev);
> -       pci_set_power_state(pci_dev, pci_choose_state(pci_dev, state));
> -
>         return 0;
>  }
>
> -static int saa7134_resume(struct pci_dev *pci_dev)
> +static int __maybe_unused saa7134_resume(struct device *dev_d)
>  {
> -       struct v4l2_device *v4l2_dev = pci_get_drvdata(pci_dev);
> +       struct v4l2_device *v4l2_dev = dev_get_drvdata(dev_d);
>         struct saa7134_dev *dev = container_of(v4l2_dev, struct saa7134_dev, v4l2_dev);
>         unsigned long flags;
>
> -       pci_set_power_state(pci_dev, PCI_D0);
> -       pci_restore_state(pci_dev);
> -
>         /* Do things that are done in saa7134_initdev ,
>                 except of initializing memory structures.*/
>
> @@ -1490,7 +1483,6 @@ static int saa7134_resume(struct pci_dev *pci_dev)
>
>         return 0;
>  }
> -#endif
>
>  /* ----------------------------------------------------------- */
>
> @@ -1522,15 +1514,14 @@ EXPORT_SYMBOL(saa7134_ts_unregister);
>
>  /* ----------------------------------------------------------- */
>
> +static SIMPLE_DEV_PM_OPS(saa7134_pm_ops, saa7134_suspend, saa7134_resume);
> +
>  static struct pci_driver saa7134_pci_driver = {
>         .name     = "saa7134",
>         .id_table = saa7134_pci_tbl,
>         .probe    = saa7134_initdev,
>         .remove   = saa7134_finidev,
> -#ifdef CONFIG_PM
> -       .suspend  = saa7134_suspend,
> -       .resume   = saa7134_resume
> -#endif
> +       .driver.pm = &saa7134_pm_ops,
>  };
>
>  static int __init saa7134_init(void)
> --
> 2.27.0
>