[PATCH v1 0/3] net: ethernet: use generic power management

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Revision v1 of 5 in this series.

5 messages, 2 authors, 2020-07-31 · open the first message on its own page

[PATCH v1 0/3] net: ethernet: use generic power management

From: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Date: 2020-07-30 06:55:24

Linux Kernel Mentee: Remove Legacy Power Management.

The purpose of this patch series is to upgrade power management in net ethernet
drivers. This has been done by upgrading .suspend() and .resume() callbacks.

The upgrade makes sure that the involvement of PCI Core does not change the
order of operations executed in a driver. Thus, does not change its behavior.

In general, drivers with legacy PM, .suspend() and .resume() make use of PCI
helper functions like pci_enable/disable_device_mem(), pci_set_power_state(),
pci_save/restore_state(), pci_enable/disable_device(), etc. to complete
their job.

The conversion requires the removal of those function calls, change the
callbacks' definition accordingly and make use of dev_pm_ops structure.

All patches are compile-tested only.

Test tools:
    - Compiler: gcc (GCC) 10.1.0
    - allmodconfig build: make -j$(nproc) W=1 all

Vaibhav Gupta (3):
  sc92031: use generic power management
  sis900: use generic power management
  tlan: use generic power management

 drivers/net/ethernet/silan/sc92031.c | 26 ++++++++---------------
 drivers/net/ethernet/sis/sis900.c    | 23 +++++++--------------
 drivers/net/ethernet/ti/tlan.c       | 31 ++++++----------------------
 3 files changed, 22 insertions(+), 58 deletions(-)

-- 
2.27.0

[PATCH v1 1/3] sc92031: use generic power management

From: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Date: 2020-07-30 06:55:33

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>
---
 drivers/net/ethernet/silan/sc92031.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/silan/sc92031.c b/drivers/net/ethernet/silan/sc92031.c
index cb043eb1bdc1..f94078f8ebe5 100644
--- a/drivers/net/ethernet/silan/sc92031.c
+++ b/drivers/net/ethernet/silan/sc92031.c

@@ -1499,15 +1499,13 @@ static void sc92031_remove(struct pci_dev *pdev)
 	pci_disable_device(pdev);
 }
 
-static int sc92031_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused sc92031_suspend(struct device *dev_d)
 {
-	struct net_device *dev = pci_get_drvdata(pdev);
+	struct net_device *dev = dev_get_drvdata(dev_d);
 	struct sc92031_priv *priv = netdev_priv(dev);
 
-	pci_save_state(pdev);
-
 	if (!netif_running(dev))
-		goto out;
+		return 0;
 
 	netif_device_detach(dev);

@@ -1521,22 +1519,16 @@ static int sc92031_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	spin_unlock_bh(&priv->lock);
 
-out:
-	pci_set_power_state(pdev, pci_choose_state(pdev, state));
-
 	return 0;
 }
 
-static int sc92031_resume(struct pci_dev *pdev)
+static int __maybe_unused sc92031_resume(struct device *dev_d)
 {
-	struct net_device *dev = pci_get_drvdata(pdev);
+	struct net_device *dev = dev_get_drvdata(dev_d);
 	struct sc92031_priv *priv = netdev_priv(dev);
 
-	pci_restore_state(pdev);
-	pci_set_power_state(pdev, PCI_D0);
-
 	if (!netif_running(dev))
-		goto out;
+		return 0;
 
 	/* Interrupts already disabled by sc92031_suspend */
 	spin_lock_bh(&priv->lock);

@@ -1553,7 +1545,6 @@ static int sc92031_resume(struct pci_dev *pdev)
 	else
 		netif_tx_disable(dev);
 
-out:
 	return 0;
 }

@@ -1565,13 +1556,14 @@ static const struct pci_device_id sc92031_pci_device_id_table[] = {
 };
 MODULE_DEVICE_TABLE(pci, sc92031_pci_device_id_table);
 
+static SIMPLE_DEV_PM_OPS(sc92031_pm_ops, sc92031_suspend, sc92031_resume);
+
 static struct pci_driver sc92031_pci_driver = {
 	.name		= SC92031_NAME,
 	.id_table	= sc92031_pci_device_id_table,
 	.probe		= sc92031_probe,
 	.remove		= sc92031_remove,
-	.suspend	= sc92031_suspend,
-	.resume		= sc92031_resume,
+	.driver.pm	= &sc92031_pm_ops,
 };
 
 module_pci_driver(sc92031_pci_driver);

-- 
2.27.0

[PATCH v1 2/3] sis900: use generic power management

From: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Date: 2020-07-30 06:55:39

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>
---
 drivers/net/ethernet/sis/sis900.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/sis/sis900.c b/drivers/net/ethernet/sis/sis900.c
index 81ed7589e33c..2af2c9816dfc 100644
--- a/drivers/net/ethernet/sis/sis900.c
+++ b/drivers/net/ethernet/sis/sis900.c

@@ -2493,11 +2493,9 @@ static void sis900_remove(struct pci_dev *pci_dev)
 	pci_release_regions(pci_dev);
 }
 
-#ifdef CONFIG_PM
-
-static int sis900_suspend(struct pci_dev *pci_dev, pm_message_t state)
+static int __maybe_unused sis900_suspend(struct device *dev)
 {
-	struct net_device *net_dev = pci_get_drvdata(pci_dev);
+	struct net_device *net_dev = dev_get_drvdata(dev);
 	struct sis900_private *sis_priv = netdev_priv(net_dev);
 	void __iomem *ioaddr = sis_priv->ioaddr;

@@ -2510,22 +2508,17 @@ static int sis900_suspend(struct pci_dev *pci_dev, pm_message_t state)
 	/* Stop the chip's Tx and Rx Status Machine */
 	sw32(cr, RxDIS | TxDIS | sr32(cr));
 
-	pci_set_power_state(pci_dev, PCI_D3hot);
-	pci_save_state(pci_dev);
-
 	return 0;
 }
 
-static int sis900_resume(struct pci_dev *pci_dev)
+static int __maybe_unused sis900_resume(struct device *dev)
 {
-	struct net_device *net_dev = pci_get_drvdata(pci_dev);
+	struct net_device *net_dev = dev_get_drvdata(dev);
 	struct sis900_private *sis_priv = netdev_priv(net_dev);
 	void __iomem *ioaddr = sis_priv->ioaddr;
 
 	if(!netif_running(net_dev))
 		return 0;
-	pci_restore_state(pci_dev);
-	pci_set_power_state(pci_dev, PCI_D0);
 
 	sis900_init_rxfilter(net_dev);

@@ -2549,17 +2542,15 @@ static int sis900_resume(struct pci_dev *pci_dev)
 
 	return 0;
 }
-#endif /* CONFIG_PM */
+
+static SIMPLE_DEV_PM_OPS(sis900_pm_ops, sis900_suspend, sis900_resume);
 
 static struct pci_driver sis900_pci_driver = {
 	.name		= SIS900_MODULE_NAME,
 	.id_table	= sis900_pci_tbl,
 	.probe		= sis900_probe,
 	.remove		= sis900_remove,
-#ifdef CONFIG_PM
-	.suspend	= sis900_suspend,
-	.resume		= sis900_resume,
-#endif /* CONFIG_PM */
+	.driver.pm	= &sis900_pm_ops,
 };
 
 static int __init sis900_init_module(void)

-- 
2.27.0

[PATCH v1 3/3] tlan: use generic power management

From: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Date: 2020-07-30 06:55:44

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>
---
 drivers/net/ethernet/ti/tlan.c | 31 ++++++-------------------------
 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/ti/tlan.c b/drivers/net/ethernet/ti/tlan.c
index 857709828058..c799945a39ef 100644
--- a/drivers/net/ethernet/ti/tlan.c
+++ b/drivers/net/ethernet/ti/tlan.c

@@ -345,33 +345,21 @@ static void tlan_stop(struct net_device *dev)
 	}
 }
 
-#ifdef CONFIG_PM
-
-static int tlan_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused tlan_suspend(struct device *dev_d)
 {
-	struct net_device *dev = pci_get_drvdata(pdev);
+	struct net_device *dev = dev_get_drvdata(dev_d);
 
 	if (netif_running(dev))
 		tlan_stop(dev);
 
 	netif_device_detach(dev);
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_wake_from_d3(pdev, false);
-	pci_set_power_state(pdev, PCI_D3hot);
 
 	return 0;
 }
 
-static int tlan_resume(struct pci_dev *pdev)
+static int __maybe_unused tlan_resume(struct device *dev_d)
 {
-	struct net_device *dev = pci_get_drvdata(pdev);
-	int rc = pci_enable_device(pdev);
-
-	if (rc)
-		return rc;
-	pci_restore_state(pdev);
-	pci_enable_wake(pdev, PCI_D0, 0);
+	struct net_device *dev = dev_get_drvdata(dev_d);
 	netif_device_attach(dev);
 
 	if (netif_running(dev))

@@ -380,21 +368,14 @@ static int tlan_resume(struct pci_dev *pdev)
 	return 0;
 }
 
-#else /* CONFIG_PM */
-
-#define tlan_suspend   NULL
-#define tlan_resume    NULL
-
-#endif /* CONFIG_PM */
-
+static SIMPLE_DEV_PM_OPS(tlan_pm_ops, tlan_suspend, tlan_resume);
 
 static struct pci_driver tlan_driver = {
 	.name		= "tlan",
 	.id_table	= tlan_pci_tbl,
 	.probe		= tlan_init_one,
 	.remove		= tlan_remove_one,
-	.suspend	= tlan_suspend,
-	.resume		= tlan_resume,
+	.driver.pm	= &tlan_pm_ops,
 };
 
 static int __init tlan_probe(void)

-- 
2.27.0

Re: [PATCH v1 0/3] net: ethernet: use generic power management

From: David Miller <davem@davemloft.net>
Date: 2020-07-31 00:43:20

From: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Date: Thu, 30 Jul 2020 12:23:33 +0530

Linux Kernel Mentee: Remove Legacy Power Management.

The purpose of this patch series is to upgrade power management in net ethernet
drivers. This has been done by upgrading .suspend() and .resume() callbacks.

The upgrade makes sure that the involvement of PCI Core does not change the
order of operations executed in a driver. Thus, does not change its behavior.

In general, drivers with legacy PM, .suspend() and .resume() make use of PCI
helper functions like pci_enable/disable_device_mem(), pci_set_power_state(),
pci_save/restore_state(), pci_enable/disable_device(), etc. to complete
their job.

The conversion requires the removal of those function calls, change the
callbacks' definition accordingly and make use of dev_pm_ops structure.

All patches are compile-tested only.

Test tools:
    - Compiler: gcc (GCC) 10.1.0
    - allmodconfig build: make -j$(nproc) W=1 all

Series applied, thanks.

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