[PATCH] can: c_can: move runtime PM enable/disable to c_can_platform

Subsystems: can network drivers, the rest

STALE1983d

6 messages, 3 authors, 2021-03-05 · open the first message on its own page

[PATCH] can: c_can: move runtime PM enable/disable to c_can_platform

From: Tong Zhang <hidden>
Date: 2021-03-01 04:17:22

Currently doing modprobe c_can_pci will make kernel complain
"Unbalanced pm_runtime_enable!", this is caused by pm_runtime_enable()
called before pm is initialized in register_candev() and doing so will
also cause it to enable twice.
This fix is similar to 227619c3ff7c, move those pm_enable/disable code to
c_can_platform.

Signed-off-by: Tong Zhang <redacted>
---
 drivers/net/can/c_can/c_can.c          | 26 ++------------------------
 drivers/net/can/c_can/c_can_platform.c |  6 +++++-
 2 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index ef474bae47a1..04f783b3d9d3 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c

@@ -212,18 +212,6 @@ static const struct can_bittiming_const c_can_bittiming_const = {
 	.brp_inc = 1,
 };
 
-static inline void c_can_pm_runtime_enable(const struct c_can_priv *priv)
-{
-	if (priv->device)
-		pm_runtime_enable(priv->device);
-}
-
-static inline void c_can_pm_runtime_disable(const struct c_can_priv *priv)
-{
-	if (priv->device)
-		pm_runtime_disable(priv->device);
-}
-
 static inline void c_can_pm_runtime_get_sync(const struct c_can_priv *priv)
 {
 	if (priv->device)

@@ -1335,7 +1323,6 @@ static const struct net_device_ops c_can_netdev_ops = {
 
 int register_c_can_dev(struct net_device *dev)
 {
-	struct c_can_priv *priv = netdev_priv(dev);
 	int err;
 
 	/* Deactivate pins to prevent DRA7 DCAN IP from being

@@ -1345,28 +1332,19 @@ int register_c_can_dev(struct net_device *dev)
 	 */
 	pinctrl_pm_select_sleep_state(dev->dev.parent);
 
-	c_can_pm_runtime_enable(priv);
-
 	dev->flags |= IFF_ECHO;	/* we support local echo */
 	dev->netdev_ops = &c_can_netdev_ops;
 
 	err = register_candev(dev);
-	if (err)
-		c_can_pm_runtime_disable(priv);
-	else
-		devm_can_led_init(dev);
-
+	if (!err)
+	  devm_can_led_init(dev);
 	return err;
 }
 EXPORT_SYMBOL_GPL(register_c_can_dev);
 
 void unregister_c_can_dev(struct net_device *dev)
 {
-	struct c_can_priv *priv = netdev_priv(dev);
-
 	unregister_candev(dev);
-
-	c_can_pm_runtime_disable(priv);
 }
 EXPORT_SYMBOL_GPL(unregister_c_can_dev);

diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 05f425ceb53a..47b251b1607c 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c

@@ -29,6 +29,7 @@
 #include <linux/list.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

@@ -386,6 +387,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, dev);
 	SET_NETDEV_DEV(dev, &pdev->dev);
 
+	pm_runtime_enable(priv->device);
 	ret = register_c_can_dev(dev);
 	if (ret) {
 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",

@@ -398,6 +400,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	return 0;
 
 exit_free_device:
+	pm_runtime_disable(priv->device);
 	free_c_can_dev(dev);
 exit:
 	dev_err(&pdev->dev, "probe failed\n");

@@ -408,9 +411,10 @@ static int c_can_plat_probe(struct platform_device *pdev)
 static int c_can_plat_remove(struct platform_device *pdev)
 {
 	struct net_device *dev = platform_get_drvdata(pdev);
+	struct c_can_priv *priv = netdev_priv(dev);
 
 	unregister_c_can_dev(dev);
-
+	pm_runtime_disable(priv->device);
 	free_c_can_dev(dev);
 
 	return 0;

-- 
2.25.1

Re: [PATCH] can: c_can: move runtime PM enable/disable to c_can_platform

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2021-03-02 05:07:06

On 28.02.2021 23:15:48, Tong Zhang wrote:

Currently doing modprobe c_can_pci will make kernel complain
"Unbalanced pm_runtime_enable!", this is caused by pm_runtime_enable()
called before pm is initialized in register_candev() and doing so will

I don't see where register_candev() is doing any pm related
initialization.

also cause it to enable twice.

This fix is similar to 227619c3ff7c, move those pm_enable/disable code to
c_can_platform.

As I understand 227619c3ff7c ("can: m_can: move runtime PM
enable/disable to m_can_platform"), PCI devices automatically enable PM,
when the "PCI device is added".

Please clarify the above point, otherwise the code looks OK, small
nitpick inline:

quoted hunk

Signed-off-by: Tong Zhang <redacted>
---
 drivers/net/can/c_can/c_can.c          | 26 ++------------------------
 drivers/net/can/c_can/c_can_platform.c |  6 +++++-
 2 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index ef474bae47a1..04f783b3d9d3 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c

@@ -212,18 +212,6 @@ static const struct can_bittiming_const c_can_bittiming_const = {
 	.brp_inc = 1,
 };
 
-static inline void c_can_pm_runtime_enable(const struct c_can_priv *priv)
-{
-	if (priv->device)
-		pm_runtime_enable(priv->device);
-}
-
-static inline void c_can_pm_runtime_disable(const struct c_can_priv *priv)
-{
-	if (priv->device)
-		pm_runtime_disable(priv->device);
-}
-
 static inline void c_can_pm_runtime_get_sync(const struct c_can_priv *priv)
 {
 	if (priv->device)

@@ -1335,7 +1323,6 @@ static const struct net_device_ops c_can_netdev_ops = {
 
 int register_c_can_dev(struct net_device *dev)
 {
-	struct c_can_priv *priv = netdev_priv(dev);
 	int err;
 
 	/* Deactivate pins to prevent DRA7 DCAN IP from being

@@ -1345,28 +1332,19 @@ int register_c_can_dev(struct net_device *dev)
 	 */
 	pinctrl_pm_select_sleep_state(dev->dev.parent);
 
-	c_can_pm_runtime_enable(priv);
-
 	dev->flags |= IFF_ECHO;	/* we support local echo */
 	dev->netdev_ops = &c_can_netdev_ops;
 
 	err = register_candev(dev);
-	if (err)
-		c_can_pm_runtime_disable(priv);
-	else
-		devm_can_led_init(dev);
-
+	if (!err)
+	  devm_can_led_init(dev);

Please indent with two tabs here.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

[PATCH v2] can: c_can: move runtime PM enable/disable to c_can_platform

From: Tong Zhang <hidden>
Date: 2021-03-02 08:10:32

Currently doing modprobe c_can_pci will make kernel complain
"Unbalanced pm_runtime_enable!", this is caused by pm_runtime_enable()
called before pm is initialized.
This fix is similar to 227619c3ff7c, move those pm_enable/disable code to
c_can_platform.

Signed-off-by: Tong Zhang <redacted>
---
 drivers/net/can/c_can/c_can.c          | 24 +-----------------------
 drivers/net/can/c_can/c_can_platform.c |  6 +++++-
 2 files changed, 6 insertions(+), 24 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index ef474bae47a1..6958830cb983 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c

@@ -212,18 +212,6 @@ static const struct can_bittiming_const c_can_bittiming_const = {
 	.brp_inc = 1,
 };
 
-static inline void c_can_pm_runtime_enable(const struct c_can_priv *priv)
-{
-	if (priv->device)
-		pm_runtime_enable(priv->device);
-}
-
-static inline void c_can_pm_runtime_disable(const struct c_can_priv *priv)
-{
-	if (priv->device)
-		pm_runtime_disable(priv->device);
-}
-
 static inline void c_can_pm_runtime_get_sync(const struct c_can_priv *priv)
 {
 	if (priv->device)

@@ -1335,7 +1323,6 @@ static const struct net_device_ops c_can_netdev_ops = {
 
 int register_c_can_dev(struct net_device *dev)
 {
-	struct c_can_priv *priv = netdev_priv(dev);
 	int err;
 
 	/* Deactivate pins to prevent DRA7 DCAN IP from being

@@ -1345,28 +1332,19 @@ int register_c_can_dev(struct net_device *dev)
 	 */
 	pinctrl_pm_select_sleep_state(dev->dev.parent);
 
-	c_can_pm_runtime_enable(priv);
-
 	dev->flags |= IFF_ECHO;	/* we support local echo */
 	dev->netdev_ops = &c_can_netdev_ops;
 
 	err = register_candev(dev);
-	if (err)
-		c_can_pm_runtime_disable(priv);
-	else
+	if (!err)
 		devm_can_led_init(dev);
-
 	return err;
 }
 EXPORT_SYMBOL_GPL(register_c_can_dev);
 
 void unregister_c_can_dev(struct net_device *dev)
 {
-	struct c_can_priv *priv = netdev_priv(dev);
-
 	unregister_candev(dev);
-
-	c_can_pm_runtime_disable(priv);
 }
 EXPORT_SYMBOL_GPL(unregister_c_can_dev);

diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 05f425ceb53a..47b251b1607c 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c

@@ -29,6 +29,7 @@
 #include <linux/list.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

@@ -386,6 +387,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, dev);
 	SET_NETDEV_DEV(dev, &pdev->dev);
 
+	pm_runtime_enable(priv->device);
 	ret = register_c_can_dev(dev);
 	if (ret) {
 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",

@@ -398,6 +400,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
 	return 0;
 
 exit_free_device:
+	pm_runtime_disable(priv->device);
 	free_c_can_dev(dev);
 exit:
 	dev_err(&pdev->dev, "probe failed\n");

@@ -408,9 +411,10 @@ static int c_can_plat_probe(struct platform_device *pdev)
 static int c_can_plat_remove(struct platform_device *pdev)
 {
 	struct net_device *dev = platform_get_drvdata(pdev);
+	struct c_can_priv *priv = netdev_priv(dev);
 
 	unregister_c_can_dev(dev);
-
+	pm_runtime_disable(priv->device);
 	free_c_can_dev(dev);
 
 	return 0;

-- 
2.25.1

Re: [PATCH] can: c_can: move runtime PM enable/disable to c_can_platform

From: Tong Zhang <hidden>
Date: 2021-03-02 08:11:21

On Mon, Mar 1, 2021 at 2:49 PM Marc Kleine-Budde [off-list ref] wrote:

On 28.02.2021 23:15:48, Tong Zhang wrote:

quoted

Currently doing modprobe c_can_pci will make kernel complain
"Unbalanced pm_runtime_enable!", this is caused by pm_runtime_enable()
called before pm is initialized in register_candev() and doing so will

I don't see where register_candev() is doing any pm related
initialization.

quoted

also cause it to enable twice.

quoted

This fix is similar to 227619c3ff7c, move those pm_enable/disable code to
c_can_platform.

As I understand 227619c3ff7c ("can: m_can: move runtime PM
enable/disable to m_can_platform"), PCI devices automatically enable PM,
when the "PCI device is added".

Hi Marc,
Thanks for the comments. I thinks you are right -- I was mislead by the trace --
I have corrected the commit log along with the indent fix in v2 patch.
Thanks again for your help,
- Tong

Please clarify the above point, otherwise the code looks OK, small
nitpick inline:

Re: [PATCH v2] can: c_can: move runtime PM enable/disable to c_can_platform

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2021-03-02 08:36:28

On 3/2/21 3:55 AM, Tong Zhang wrote:

Currently doing modprobe c_can_pci will make kernel complain
"Unbalanced pm_runtime_enable!", this is caused by pm_runtime_enable()
called before pm is initialized.
This fix is similar to 227619c3ff7c, move those pm_enable/disable code to
c_can_platform.

Signed-off-by: Tong Zhang <redacted>

Applied to linux-can/testing.

Thanks,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

Re: [PATCH v2] can: c_can: move runtime PM enable/disable to c_can_platform

From: Uwe Kleine-König <hidden>
Date: 2021-03-05 11:33:40

On Mon, Mar 01, 2021 at 09:55:40PM -0500, Tong Zhang wrote:

Currently doing modprobe c_can_pci will make kernel complain
"Unbalanced pm_runtime_enable!", this is caused by pm_runtime_enable()
called before pm is initialized.
This fix is similar to 227619c3ff7c, move those pm_enable/disable code to
c_can_platform.

I can confirm this makes the warning go away on a Congatec Atom board. I
didn't do any further runtime tests.

Tested-by: Uwe Kleine-König <redacted>

Thanks
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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