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From:   Vaibhav Gupta <vaibhavgupta40@gmail.com>
To:     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>,
        Damien Le Moal <Damien.LeMoal@wdc.com>
Cc:     Vaibhav Gupta <vaibhavgupta40@gmail.com>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Shuah Khan <skhan@linuxfoundation.org>,
        Damien Le Moal <damien.lemoal@wdc.com>
Subject: [PATCH v4 3/3] skd: use generic power management
Date:   Thu, 14 Jan 2021 17:24:23 +0530
Message-Id: <20210114115423.52414-4-vaibhavgupta40@gmail.com>
In-Reply-To: <20210114115423.52414-1-vaibhavgupta40@gmail.com>
References: <20200722083335.50068-1-vaibhavgupta40@gmail.com>
 <20210114115423.52414-1-vaibhavgupta40@gmail.com>
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Drivers using legacy power management .suspen()/.resume() callbacks
have to manage PCI states and device's PM states themselves. They also
need to take care of standard configuration registers.

Switch to generic power management framework using a single
"struct dev_pm_ops" variable to take the unnecessary load from the driver.
This also avoids the need for the driver to directly call most of the PCI
helper functions and device power state control functions, as through
the generic framework PCI Core takes care of the necessary operations,
and drivers are required to do only device-specific jobs.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.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 a962b4551bed..8194b58525e2 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -3317,10 +3317,11 @@ 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) {
@@ -3339,18 +3340,15 @@ 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) {
@@ -3358,16 +3356,8 @@ 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));
@@ -3376,7 +3366,6 @@ 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,
@@ -3429,10 +3418,6 @@ 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;
 }
 
@@ -3452,13 +3437,14 @@ 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,
 };
 
-- 
2.30.0