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From:   Damien Le Moal <Damien.LeMoal@wdc.com>
To:     Vaibhav Gupta <vaibhavgupta40@gmail.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Bjorn Helgaas <bjorn@helgaas.com>,
        Vaibhav Gupta <vaibhav.varodek@gmail.com>,
        Jens Axboe <axboe@kernel.dk>,
        Joshua Morris <josh.h.morris@us.ibm.com>,
        Philip Kelleher <pjk1939@linux.ibm.com>
CC:     "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-kernel-mentees@lists.linuxfoundation.org" 
        <linux-kernel-mentees@lists.linuxfoundation.org>,
        Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH v3 3/3] skd: use generic power management
Thread-Topic: [PATCH v3 3/3] skd: use generic power management
Thread-Index: AQHWYAMLHus2S/WLN0GIM31Ogd6sQg==
Date:   Mon, 27 Jul 2020 02:14:31 +0000
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References: <ea5881cdfd4d612193feed646ce89f253a36db69.camel@wdc.com>
 <20200722083335.50068-1-vaibhavgupta40@gmail.com>
 <20200722083335.50068-4-vaibhavgupta40@gmail.com>
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On 2020/07/22 17:35, Vaibhav Gupta wrote:=0A=
> Drivers using legacy power management .suspen()/.resume() callbacks=0A=
> have to manage PCI states and device's PM states themselves. They also=0A=
> need to take care of standard configuration registers.=0A=
> =0A=
> Switch to generic power management framework using a single=0A=
> "struct dev_pm_ops" variable to take the unnecessary load from the driver=
.=0A=
> This also avoids the need for the driver to directly call most of the PCI=
=0A=
> helper functions and device power state control functions, as through=0A=
> the generic framework PCI Core takes care of the necessary operations,=0A=
> and drivers are required to do only device-specific jobs.=0A=
> =0A=
> Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>=0A=
> ---=0A=
>  drivers/block/skd_main.c | 30 ++++++++----------------------=0A=
>  1 file changed, 8 insertions(+), 22 deletions(-)=0A=
> =0A=
> diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c=0A=
> index 51569c199a6c..7f2d42900b38 100644=0A=
> --- a/drivers/block/skd_main.c=0A=
> +++ b/drivers/block/skd_main.c=0A=
> @@ -3315,10 +3315,11 @@ static void skd_pci_remove(struct pci_dev *pdev)=
=0A=
>  	return;=0A=
>  }=0A=
>  =0A=
> -static int skd_pci_suspend(struct pci_dev *pdev, pm_message_t state)=0A=
> +static int __maybe_unused skd_pci_suspend(struct device *dev)=0A=
>  {=0A=
>  	int i;=0A=
>  	struct skd_device *skdev;=0A=
> +	struct pci_dev *pdev =3D to_pci_dev(dev);=0A=
>  =0A=
>  	skdev =3D pci_get_drvdata(pdev);=0A=
>  	if (!skdev) {=0A=
> @@ -3337,18 +3338,15 @@ static int skd_pci_suspend(struct pci_dev *pdev, =
pm_message_t state)=0A=
>  	if (skdev->pcie_error_reporting_is_enabled)=0A=
>  		pci_disable_pcie_error_reporting(pdev);=0A=
>  =0A=
> -	pci_release_regions(pdev);=0A=
> -	pci_save_state(pdev);=0A=
> -	pci_disable_device(pdev);=0A=
> -	pci_set_power_state(pdev, pci_choose_state(pdev, state));=0A=
>  	return 0;=0A=
>  }=0A=
>  =0A=
> -static int skd_pci_resume(struct pci_dev *pdev)=0A=
> +static int __maybe_unused skd_pci_resume(struct device *dev)=0A=
>  {=0A=
>  	int i;=0A=
>  	int rc =3D 0;=0A=
>  	struct skd_device *skdev;=0A=
> +	struct pci_dev *pdev =3D to_pci_dev(dev);=0A=
>  =0A=
>  	skdev =3D pci_get_drvdata(pdev);=0A=
>  	if (!skdev) {=0A=
> @@ -3356,16 +3354,8 @@ static int skd_pci_resume(struct pci_dev *pdev)=0A=
>  		return -1;=0A=
>  	}=0A=
>  =0A=
> -	pci_set_power_state(pdev, PCI_D0);=0A=
> -	pci_enable_wake(pdev, PCI_D0, 0);=0A=
> -	pci_restore_state(pdev);=0A=
> +	device_wakeup_disable(dev);=0A=
>  =0A=
> -	rc =3D pci_enable_device(pdev);=0A=
> -	if (rc)=0A=
> -		return rc;=0A=
> -	rc =3D pci_request_regions(pdev, DRV_NAME);=0A=
> -	if (rc)=0A=
> -		goto err_out;=0A=
>  	rc =3D dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));=0A=
>  	if (rc)=0A=
>  		rc =3D dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));=0A=
> @@ -3374,7 +3364,6 @@ static int skd_pci_resume(struct pci_dev *pdev)=0A=
>  		goto err_out_regions;=0A=
>  	}=0A=
>  =0A=
> -	pci_set_master(pdev);=0A=
>  	rc =3D pci_enable_pcie_error_reporting(pdev);=0A=
>  	if (rc) {=0A=
>  		dev_err(&pdev->dev,=0A=
> @@ -3427,10 +3416,6 @@ static int skd_pci_resume(struct pci_dev *pdev)=0A=
>  		pci_disable_pcie_error_reporting(pdev);=0A=
>  =0A=
>  err_out_regions:=0A=
> -	pci_release_regions(pdev);=0A=
> -=0A=
> -err_out:=0A=
> -	pci_disable_device(pdev);=0A=
>  	return rc;=0A=
>  }=0A=
>  =0A=
> @@ -3450,13 +3435,14 @@ static void skd_pci_shutdown(struct pci_dev *pdev=
)=0A=
>  	skd_stop_device(skdev);=0A=
>  }=0A=
>  =0A=
> +static SIMPLE_DEV_PM_OPS(skd_pci_pm_ops, skd_pci_suspend, skd_pci_resume=
);=0A=
> +=0A=
>  static struct pci_driver skd_driver =3D {=0A=
>  	.name		=3D DRV_NAME,=0A=
>  	.id_table	=3D skd_pci_tbl,=0A=
>  	.probe		=3D skd_pci_probe,=0A=
>  	.remove		=3D skd_pci_remove,=0A=
> -	.suspend	=3D skd_pci_suspend,=0A=
> -	.resume		=3D skd_pci_resume,=0A=
> +	.driver.pm	=3D &skd_pci_pm_ops,=0A=
>  	.shutdown	=3D skd_pci_shutdown,=0A=
>  };=0A=
>  =0A=
> =0A=
=0A=
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>=0A=
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>=0A=
=0A=
=0A=
-- =0A=
Damien Le Moal=0A=
Western Digital Research=0A=