[PATCH] power: Destroy IDRs on module exit

[PATCH] power: Destroy IDRs on module exit

[Johannes Thumshirn]

Destroy IDRs on module exit, freeing the resources for
* bq2415x_charger.c
* ds2782_battery.c
* ltc2941-battery-gauge.c

The drivers had to be converted to "ordinary" module_init()/module_exit()
style drivers instead of using module_i2c_driver.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/power/bq2415x_charger.c       | 20 +++++++++++++++++++-
 drivers/power/ds2782_battery.c        | 20 +++++++++++++++++++-
 drivers/power/ltc2941-battery-gauge.c | 20 +++++++++++++++++++-
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/drivers/power/bq2415x_charger.c b/drivers/power/bq2415x_charger.c
index e98dcb6..38f4208 100644
--- a/drivers/power/bq2415x_charger.c
+++ b/drivers/power/bq2415x_charger.c
@@ -1773,7 +1773,25 @@ static struct i2c_driver bq2415x_driver = {
 	.remove = bq2415x_remove,
 	.id_table = bq2415x_i2c_id_table,
 };
-module_i2c_driver(bq2415x_driver);
+
+static int __init bq2415x_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&bq2415x_driver);
+	if (ret)
+		printk(KERN_ERR "Unable to register bq2415x-battery driver\n");
+
+	return ret;
+}
+module_init(bq2415x_init);
+
+static void __exit bq2415x_exit(void)
+{
+	i2c_del_driver(&bq2415x_driver);
+	idr_destroy(&bq2415x_id);
+}
+module_exit(bq2415x_exit);
 
 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
 MODULE_DESCRIPTION("bq2415x charger driver");
diff --git a/drivers/power/ds2782_battery.c b/drivers/power/ds2782_battery.c
index ed4d756..410bc9d 100644
--- a/drivers/power/ds2782_battery.c
+++ b/drivers/power/ds2782_battery.c
@@ -468,7 +468,25 @@ static struct i2c_driver ds278x_battery_driver = {
 	.remove		= ds278x_battery_remove,
 	.id_table	= ds278x_id,
 };
-module_i2c_driver(ds278x_battery_driver);
+
+static int __init ds2782_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&ds278x_battery_driver);
+	if (ret)
+		printk(KERN_ERR "Unable to register ds2782-battery driver\n");
+
+	return ret;
+}
+module_init(ds2782_init);
+
+static void __exit ds2782_exit(void)
+{
+	i2c_del_driver(&ds278x_battery_driver);
+	idr_destroy(&battery_id);
+}
+module_exit(ds2782_exit);
 
 MODULE_AUTHOR("Ryan Mallon");
 MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver");
diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c
index daeb086..6fbbcd2 100644
--- a/drivers/power/ltc2941-battery-gauge.c
+++ b/drivers/power/ltc2941-battery-gauge.c
@@ -544,7 +544,25 @@ static struct i2c_driver ltc294x_driver = {
 	.remove		= ltc294x_i2c_remove,
 	.id_table	= ltc294x_i2c_id,
 };
-module_i2c_driver(ltc294x_driver);
+
+static int __init ltc294x_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&ltc294x_driver);
+	if (ret)
+		printk(KERN_ERR "Unable to register bq2415x-battery driver\n");
+
+	return ret;
+}
+module_init(ltc294x_init);
+
+static void __exit ltc294x_exit(void)
+{
+	i2c_del_driver(&ltc294x_driver);
+	idr_destroy(&ltc294x_id);
+}
+module_exit(ltc294x_exit);
 
 MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems");
 MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products");
-- 
2.4.5

Re: [PATCH] power: Destroy IDRs on module exit

[Oliver Neukum]

On Tue, 2015-07-14 at 11:16 +0200, Johannes Thumshirn wrote:
> Destroy IDRs on module exit, freeing the resources for
> * bq2415x_charger.c
> * ds2782_battery.c
> * ltc2941-battery-gauge.c
> 
> The drivers had to be converted to "ordinary"
> module_init()/module_exit()
> style drivers instead of using module_i2c_driver.

That is a drawback. How about adding a pointer to the idr
to "struct i2c_driver" and destroy it in generic code?

	Regards
		Oliver

Re: [PATCH] power: Destroy IDRs on module exit

[Pali Rohár]

On Tuesday 14 July 2015 11:16:14 Johannes Thumshirn wrote:
> Destroy IDRs on module exit, freeing the resources for
> * bq2415x_charger.c
> * ds2782_battery.c
> * ltc2941-battery-gauge.c
> 
> The drivers had to be converted to "ordinary" module_init()/module_exit()
> style drivers instead of using module_i2c_driver.
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---
>  drivers/power/bq2415x_charger.c       | 20 +++++++++++++++++++-
>  drivers/power/ds2782_battery.c        | 20 +++++++++++++++++++-
>  drivers/power/ltc2941-battery-gauge.c | 20 +++++++++++++++++++-
>  3 files changed, 57 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/power/bq2415x_charger.c b/drivers/power/bq2415x_charger.c
> index e98dcb6..38f4208 100644
> --- a/drivers/power/bq2415x_charger.c
> +++ b/drivers/power/bq2415x_charger.c
> @@ -1773,7 +1773,25 @@ static struct i2c_driver bq2415x_driver = {
>  	.remove = bq2415x_remove,
>  	.id_table = bq2415x_i2c_id_table,
>  };
> -module_i2c_driver(bq2415x_driver);
> +
> +static int __init bq2415x_init(void)
> +{
> +	int ret;
> +
> +	ret = i2c_add_driver(&bq2415x_driver);
> +	if (ret)
> +		printk(KERN_ERR "Unable to register bq2415x-battery driver\n");
> +
> +	return ret;
> +}
> +module_init(bq2415x_init);
> +
> +static void __exit bq2415x_exit(void)
> +{
> +	i2c_del_driver(&bq2415x_driver);
> +	idr_destroy(&bq2415x_id);
> +}
> +module_exit(bq2415x_exit);
>  
>  MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
>  MODULE_DESCRIPTION("bq2415x charger driver");
> diff --git a/drivers/power/ds2782_battery.c b/drivers/power/ds2782_battery.c
> index ed4d756..410bc9d 100644
> --- a/drivers/power/ds2782_battery.c
> +++ b/drivers/power/ds2782_battery.c
> @@ -468,7 +468,25 @@ static struct i2c_driver ds278x_battery_driver = {
>  	.remove		= ds278x_battery_remove,
>  	.id_table	= ds278x_id,
>  };
> -module_i2c_driver(ds278x_battery_driver);
> +
> +static int __init ds2782_init(void)
> +{
> +	int ret;
> +
> +	ret = i2c_add_driver(&ds278x_battery_driver);
> +	if (ret)
> +		printk(KERN_ERR "Unable to register ds2782-battery driver\n");
> +
> +	return ret;
> +}
> +module_init(ds2782_init);
> +
> +static void __exit ds2782_exit(void)
> +{
> +	i2c_del_driver(&ds278x_battery_driver);
> +	idr_destroy(&battery_id);
> +}
> +module_exit(ds2782_exit);
>  
>  MODULE_AUTHOR("Ryan Mallon");
>  MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver");
> diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c
> index daeb086..6fbbcd2 100644
> --- a/drivers/power/ltc2941-battery-gauge.c
> +++ b/drivers/power/ltc2941-battery-gauge.c
> @@ -544,7 +544,25 @@ static struct i2c_driver ltc294x_driver = {
>  	.remove		= ltc294x_i2c_remove,
>  	.id_table	= ltc294x_i2c_id,
>  };
> -module_i2c_driver(ltc294x_driver);
> +
> +static int __init ltc294x_init(void)
> +{
> +	int ret;
> +
> +	ret = i2c_add_driver(&ltc294x_driver);
> +	if (ret)
> +		printk(KERN_ERR "Unable to register bq2415x-battery driver\n");
> +
> +	return ret;
> +}
> +module_init(ltc294x_init);
> +
> +static void __exit ltc294x_exit(void)
> +{
> +	i2c_del_driver(&ltc294x_driver);
> +	idr_destroy(&ltc294x_id);
> +}
> +module_exit(ltc294x_exit);
>  
>  MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems");
>  MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products");

I'm feeling that there is something wrong with idr API. There is no idr
code in __init functions, so why it is needed for __exit? idr functions
are used in devices, not in global module.

-- 
Pali Rohár
pali.rohar@gmail.com

Re: [PATCH] power: Destroy IDRs on module exit

[Sebastian Reichel]

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[+CC: Tejun Heo <tj@kernel.org>, for being very active in lib/idr.c]

Hi,

On Tue, Jul 14, 2015 at 11:16:14AM +0200, Johannes Thumshirn wrote:
> Destroy IDRs on module exit, freeing the resources for
> * bq2415x_charger.c
> * ds2782_battery.c
> * ltc2941-battery-gauge.c

You missed bq27x00_battery.c. Maybe a coccinelle script should be
written?

> The drivers had to be converted to "ordinary" module_init()/module_exit()
> style drivers instead of using module_i2c_driver.

mh I would prefer another solution. How about adding something
like this:

static void idr_remove_and_destroy(struct idr *idp, int id)
{
    idr_remove(idp, id);
    if (idr_is_empty(idp)
        idr_destroy(idp);
}

If that is called by the drivers instead of idr_remove(), there
should be no need for adding idr_destroy to module_exit().

-- Sebastian

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Re: [PATCH] power: Destroy IDRs on module exit

[Johannes Thumshirn]

Sebastian Reichel <sre@kernel.org> writes:

> [+CC: Tejun Heo <tj@kernel.org>, for being very active in lib/idr.c]
>
> Hi,
>
> On Tue, Jul 14, 2015 at 11:16:14AM +0200, Johannes Thumshirn wrote:
>> Destroy IDRs on module exit, freeing the resources for
>> * bq2415x_charger.c
>> * ds2782_battery.c
>> * ltc2941-battery-gauge.c
>
> You missed bq27x00_battery.c. Maybe a coccinelle script should be
> written?

I already did this one that last week (I think), it should've been in
your INBOX (I hope).

>> The drivers had to be converted to "ordinary" module_init()/module_exit()
>> style drivers instead of using module_i2c_driver.
>
> mh I would prefer another solution. How about adding something
> like this:
>
> static void idr_remove_and_destroy(struct idr *idp, int id)
> {
>     idr_remove(idp, id);
>     if (idr_is_empty(idp)
>         idr_destroy(idp);
> }
>
> If that is called by the drivers instead of idr_remove(), there
> should be no need for adding idr_destroy to module_exit().
>

This would be an option.

[Copied a part of Palin's reply in here as well]
Palin> I'm feeling that there is something wrong with idr API. There is no idr
Palin> code in __init functions, so why it is needed for __exit? idr functions
Palin> are used in devices, not in global module.

but I start getting a bit puzzled about the whole IDR thing. Further
grepping through the tree revealed even more drivers doing
DEFINE_ID{A,R} but not all doing the destroy calls afterwards. Maybe
Tejun can clarify on this.

Johannes

Re: [PATCH] power: Destroy IDRs on module exit

[Sebastian Reichel]

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Hi,

On Tue, Jul 14, 2015 at 12:48:31PM +0200, Johannes Thumshirn wrote:
> Sebastian Reichel <sre@kernel.org> writes:
> > On Tue, Jul 14, 2015 at 11:16:14AM +0200, Johannes Thumshirn wrote:
> >> Destroy IDRs on module exit, freeing the resources for
> >> * bq2415x_charger.c
> >> * ds2782_battery.c
> >> * ltc2941-battery-gauge.c
> >
> > You missed bq27x00_battery.c. Maybe a coccinelle script should be
> > written?
> 
> I already did this one that last week (I think), it should've been in
> your INBOX (I hope).

Right. I marked that one as read assuming you would write a new
version of the patch changing all drivers. Please change all drivers
in one patch in the next version.

-- Sebastian

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