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 <[email protected]>
---
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
On Mon, Mar 1, 2021 at 2:49 PM Marc Kleine-Budde <[email protected]> wrote:
>
> 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".
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:
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:
> Signed-off-by: Tong Zhang <[email protected]>
> ---
> 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 |