[Linux-kernel-mentees] [PATCH v4 19/29] scsi: pm_8001: use generic power management

Vaibhav Gupta vaibhavgupta40 at gmail.com
Mon Nov 2 16:47:20 UTC 2020


Drivers should do only device-specific jobs. But in general, drivers using
legacy PCI PM framework for .suspend()/.resume() have to manage many PCI
PM-related tasks themselves which can be done by PCI Core itself. This
brings extra load on the driver and it directly calls PCI helper functions
to handle them.

Switch to the new generic framework by updating function signatures and
define a "struct dev_pm_ops" variable to bind PM callbacks. Also, remove
unnecessary calls to the PCI Helper functions along with the legacy
.suspend & .resume bindings.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 drivers/scsi/pm8001/pm8001_init.c | 45 +++++++++++--------------------
 1 file changed, 16 insertions(+), 29 deletions(-)

diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index d47ed9a33173..7a732fd09b38 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -1257,23 +1257,21 @@ static void pm8001_pci_remove(struct pci_dev *pdev)
 
 /**
  * pm8001_pci_suspend - power management suspend main entry point
- * @pdev: PCI device struct
- * @state: PM state change to (usually PCI_D3)
+ * @dev: Device struct
  *
  * Returns 0 success, anything else error.
  */
-static int pm8001_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused pm8001_pci_suspend(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct sas_ha_struct *sha = pci_get_drvdata(pdev);
-	struct pm8001_hba_info *pm8001_ha;
+	struct pm8001_hba_info *pm8001_ha = sha->lldd_ha;
 	int  i, j;
-	u32 device_state;
-	pm8001_ha = sha->lldd_ha;
 	sas_suspend_ha(sha);
 	flush_workqueue(pm8001_wq);
 	scsi_block_requests(pm8001_ha->shost);
 	if (!pdev->pm_cap) {
-		dev_err(&pdev->dev, " PCI PM not supported\n");
+		dev_err(dev, " PCI PM not supported\n");
 		return -ENODEV;
 	}
 	PM8001_CHIP_DISP->interrupt_disable(pm8001_ha, 0xFF);
@@ -1296,24 +1294,21 @@ static int pm8001_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 		for (j = 0; j < PM8001_MAX_MSIX_VEC; j++)
 			tasklet_kill(&pm8001_ha->tasklet[j]);
 #endif
-	device_state = pci_choose_state(pdev, state);
 	pm8001_printk("pdev=0x%p, slot=%s, entering "
-		      "operating state [D%d]\n", pdev,
-		      pm8001_ha->name, device_state);
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_set_power_state(pdev, device_state);
+		"suspended state\n", pdev,
+		pm8001_ha->name);
 	return 0;
 }
 
 /**
  * pm8001_pci_resume - power management resume main entry point
- * @pdev: PCI device struct
+ * @dev: Device struct
  *
  * Returns 0 success, anything else error.
  */
-static int pm8001_pci_resume(struct pci_dev *pdev)
+static int __maybe_unused pm8001_pci_resume(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct sas_ha_struct *sha = pci_get_drvdata(pdev);
 	struct pm8001_hba_info *pm8001_ha;
 	int rc;
@@ -1326,16 +1321,6 @@ static int pm8001_pci_resume(struct pci_dev *pdev)
 	pm8001_printk("pdev=0x%p, slot=%s, resuming from previous "
 		"operating state [D%d]\n", pdev, pm8001_ha->name, device_state);
 
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
-	rc = pci_enable_device(pdev);
-	if (rc) {
-		pm8001_printk("slot=%s Enable device failed during resume\n",
-			      pm8001_ha->name);
-		goto err_out_enable;
-	}
-
-	pci_set_master(pdev);
 	rc = pci_go_44(pdev);
 	if (rc)
 		goto err_out_disable;
@@ -1396,8 +1381,7 @@ static int pm8001_pci_resume(struct pci_dev *pdev)
 
 err_out_disable:
 	scsi_remove_host(pm8001_ha->shost);
-	pci_disable_device(pdev);
-err_out_enable:
+
 	return rc;
 }
 
@@ -1480,13 +1464,16 @@ static struct pci_device_id pm8001_pci_table[] = {
 	{} /* terminate list */
 };
 
+static SIMPLE_DEV_PM_OPS(pm8001_pci_pm_ops,
+			 pm8001_pci_suspend,
+			 pm8001_pci_resume);
+
 static struct pci_driver pm8001_pci_driver = {
 	.name		= DRV_NAME,
 	.id_table	= pm8001_pci_table,
 	.probe		= pm8001_pci_probe,
 	.remove		= pm8001_pci_remove,
-	.suspend	= pm8001_pci_suspend,
-	.resume		= pm8001_pci_resume,
+	.driver.pm	= &pm8001_pci_pm_ops,
 };
 
 /**
-- 
2.28.0



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