[Linux-kernel-mentees] [PATCH v1 3/3] via-agp: use generic power management

Vaibhav Gupta vaibhavgupta40 at gmail.com
Fri Jul 17 07:49:37 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() and pci_set_power_state() to do required
operations. In generic mode, they are no longer needed.

Change function parameter in .resume() to "struct device*" type. Use
to_pci_dev() to get "struct pci_dev*" variable.

After upgrading, .suspend() became an empty-body function, hence defined as
NULL.

Compile-tested only.

Signed-off-by: Vaibhav Gupta <vaibhavgupta40 at gmail.com>
---
 drivers/char/agp/via-agp.c | 25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/drivers/char/agp/via-agp.c b/drivers/char/agp/via-agp.c
index 87a92a044570..afa941df7d44 100644
--- a/drivers/char/agp/via-agp.c
+++ b/drivers/char/agp/via-agp.c
@@ -492,22 +492,11 @@ static void agp_via_remove(struct pci_dev *pdev)
 	agp_put_bridge(bridge);
 }
 
-#ifdef CONFIG_PM
+#define agp_via_suspend NULL
 
-static int agp_via_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused agp_via_resume(struct device *dev)
 {
-	pci_save_state (pdev);
-	pci_set_power_state (pdev, PCI_D3hot);
-
-	return 0;
-}
-
-static int agp_via_resume(struct pci_dev *pdev)
-{
-	struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
-
-	pci_set_power_state (pdev, PCI_D0);
-	pci_restore_state(pdev);
+	struct agp_bridge_data *bridge = dev_get_drvdata(dev);
 
 	if (bridge->driver == &via_agp3_driver)
 		return via_configure_agp3();
@@ -517,8 +506,6 @@ static int agp_via_resume(struct pci_dev *pdev)
 	return 0;
 }
 
-#endif /* CONFIG_PM */
-
 /* must be the same order as name table above */
 static const struct pci_device_id agp_via_pci_table[] = {
 #define ID(x) \
@@ -567,16 +554,14 @@ static const struct pci_device_id agp_via_pci_table[] = {
 
 MODULE_DEVICE_TABLE(pci, agp_via_pci_table);
 
+static SIMPLE_DEV_PM_OPS(agp_via_pm_ops, agp_via_suspend, agp_via_resume);
 
 static struct pci_driver agp_via_pci_driver = {
 	.name		= "agpgart-via",
 	.id_table	= agp_via_pci_table,
 	.probe		= agp_via_probe,
 	.remove		= agp_via_remove,
-#ifdef CONFIG_PM
-	.suspend	= agp_via_suspend,
-	.resume		= agp_via_resume,
-#endif
+	.driver.pm	= &agp_via_pm_ops,
 };
 
 
-- 
2.27.0



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