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Message-ID: <20200721070939.GB51743@gmail.com>
Date: Tue, 21 Jul 2020 12:39:39 +0530
From: Vaibhav Gupta <vaibhavgupta40@...il.com>
To: Damien Le Moal <Damien.LeMoal@....com>
Cc: Bjorn Helgaas <helgaas@...nel.org>,
Bjorn Helgaas <bhelgaas@...gle.com>,
Bjorn Helgaas <bjorn@...gaas.com>,
Vaibhav Gupta <vaibhav.varodek@...il.com>,
Jens Axboe <axboe@...nel.dk>,
Joshua Morris <josh.h.morris@...ibm.com>,
Philip Kelleher <pjk1939@...ux.ibm.com>,
"linux-block@...r.kernel.org" <linux-block@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-kernel-mentees@...ts.linuxfoundation.org"
<linux-kernel-mentees@...ts.linuxfoundation.org>,
Shuah Khan <skhan@...uxfoundation.org>
Subject: Re: [PATCH v2 3/3] skd: use generic power management
On Tue, Jul 21, 2020 at 02:57:28AM +0000, Damien Le Moal wrote:
> On 2020/07/20 22:32, 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.
>
> This commit message is rather vague, and the last sentence actually does not
> describe correctly the change. What about something very simple, yet clear, like
> this:
>
> skd: use generic power management
>
> Switch from the legacy .suspend()/.resume() power management interface to the
> generic power management interface using the single .driver.pm() method. This
> avoids the need for the driver to directly call most of the PCI helper functions
> and device power state control functions as the generic power management
> interface takes care of the necessary operations.
>
Okay. I will improve on it. Just inform me after testing that if any other
changes are required. I guess [PATCH 1/3] and [PATCH 2/3] are okay, so I will
only send v3 of [PATCH 3/3] after suggested changes.
> >
> > Compile-tested only.
> >
> > Signed-off-by: Vaibhav Gupta <vaibhavgupta40@...il.com>
> > ---
> > drivers/block/skd_main.c | 30 ++++++++----------------------
> > 1 file changed, 8 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> > index 51569c199a6c..7f2d42900b38 100644
> > --- a/drivers/block/skd_main.c
> > +++ b/drivers/block/skd_main.c
> > @@ -3315,10 +3315,11 @@ 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);
> >
> > skdev = pci_get_drvdata(pdev);
> > if (!skdev) {
> > @@ -3337,18 +3338,15 @@ 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;
> > + struct pci_dev *pdev = to_pci_dev(dev);
> >
> > skdev = pci_get_drvdata(pdev);
> > if (!skdev) {
> > @@ -3356,16 +3354,8 @@ static int skd_pci_resume(struct pci_dev *pdev)
> > 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 +3364,6 @@ 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 +3416,6 @@ 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 +3435,14 @@ 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,
> > };
> >
> >
>
> Apart from the commit message, this looks OK to me.
> I will give this a spin today on the hardware to check.
>
Thanks!
--Vaibhav Gupta
>
> --
> Damien Le Moal
> Western Digital Research
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