[Linux-kernel-mentees] [PATCH v2 1/3] mtip32xx: use generic power management

Vaibhav Gupta vaibhavgupta40 at gmail.com
Mon Jul 20 13:30:00 UTC 2020


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_disable_device(), pcim_enable_device(),
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 dev_get_drvdata() to get drv data.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 drivers/block/mtip32xx/mtip32xx.c | 54 +++++++------------------------
 1 file changed, 12 insertions(+), 42 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index f6bafa9a68b9..7d1280952b35 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -4246,14 +4246,13 @@ static void mtip_pci_remove(struct pci_dev *pdev)
  *	0  Success
  *	<0 Error
  */
-static int mtip_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
+static int __maybe_unused mtip_pci_suspend(struct device *dev)
 {
 	int rv = 0;
-	struct driver_data *dd = pci_get_drvdata(pdev);
+	struct driver_data *dd = dev_get_drvdata(dev);
 
 	if (!dd) {
-		dev_err(&pdev->dev,
-			"Driver private datastructure is NULL\n");
+		dev_err(dev, "Driver private datastructure is NULL\n");
 		return -EFAULT;
 	}
 
@@ -4261,21 +4260,8 @@ static int mtip_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
 
 	/* Disable ports & interrupts then send standby immediate */
 	rv = mtip_block_suspend(dd);
-	if (rv < 0) {
-		dev_err(&pdev->dev,
-			"Failed to suspend controller\n");
-		return rv;
-	}
-
-	/*
-	 * Save the pci config space to pdev structure &
-	 * disable the device
-	 */
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-
-	/* Move to Low power state*/
-	pci_set_power_state(pdev, PCI_D3hot);
+	if (rv < 0)
+		dev_err(dev, "Failed to suspend controller\n");
 
 	return rv;
 }
@@ -4287,42 +4273,25 @@ static int mtip_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
  *      0  Success
  *      <0 Error
  */
-static int mtip_pci_resume(struct pci_dev *pdev)
+static int __maybe_unused mtip_pci_resume(struct device *dev)
 {
 	int rv = 0;
 	struct driver_data *dd;
 
-	dd = pci_get_drvdata(pdev);
+	dd = dev_get_drvdata(dev);
 	if (!dd) {
-		dev_err(&pdev->dev,
-			"Driver private datastructure is NULL\n");
+		dev_err(dev, "Driver private datastructure is NULL\n");
 		return -EFAULT;
 	}
 
-	/* Move the device to active State */
-	pci_set_power_state(pdev, PCI_D0);
-
-	/* Restore PCI configuration space */
-	pci_restore_state(pdev);
-
-	/* Enable the PCI device*/
-	rv = pcim_enable_device(pdev);
-	if (rv < 0) {
-		dev_err(&pdev->dev,
-			"Failed to enable card during resume\n");
-		goto err;
-	}
-	pci_set_master(pdev);
-
 	/*
 	 * Calls hbaReset, initPort, & startPort function
 	 * then enables interrupts
 	 */
 	rv = mtip_block_resume(dd);
 	if (rv < 0)
-		dev_err(&pdev->dev, "Unable to resume\n");
+		dev_err(dev, "Unable to resume\n");
 
-err:
 	clear_bit(MTIP_DDF_RESUME_BIT, &dd->dd_flag);
 
 	return rv;
@@ -4353,14 +4322,15 @@ static const struct pci_device_id mtip_pci_tbl[] = {
 	{ 0 }
 };
 
+static SIMPLE_DEV_PM_OPS(mtip_pci_pm_ops, mtip_pci_suspend, mtip_pci_resume);
+
 /* Structure that describes the PCI driver functions. */
 static struct pci_driver mtip_pci_driver = {
 	.name			= MTIP_DRV_NAME,
 	.id_table		= mtip_pci_tbl,
 	.probe			= mtip_pci_probe,
 	.remove			= mtip_pci_remove,
-	.suspend		= mtip_pci_suspend,
-	.resume			= mtip_pci_resume,
+	.driver.pm		= &mtip_pci_pm_ops,
 	.shutdown		= mtip_pci_shutdown,
 };
 
-- 
2.27.0



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