[PATCH] clocksource/drivers/integrator-ap: add missing of_node_put()

[PATCH] clocksource/drivers/integrator-ap: add missing of_node_put()

[Yangtao Li]

of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
integrator_ap_timer_init_of() doesn't do that, so fix it.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
---
 drivers/clocksource/timer-integrator-ap.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
index 76e526f58620..1f04069470bb 100644
--- a/drivers/clocksource/timer-integrator-ap.c
+++ b/drivers/clocksource/timer-integrator-ap.c
@@ -177,7 +177,7 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
 {
 	const char *path;
 	void __iomem *base;
-	int err;
+	int err,rc = 0;
 	int irq;
 	struct clk *clk;
 	unsigned long rate;
@@ -210,26 +210,34 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
 				"arm,timer-secondary", &path);
 	if (err) {
 		pr_warn("Failed to read property\n");
-		return err;
+		rc = err;
+		goto out_put_pri_node;
 	}
 
 
 	sec_node = of_find_node_by_path(path);
 
-	if (node == pri_node)
+	if (node == pri_node){
 		/* The primary timer lacks IRQ, use as clocksource */
-		return integrator_clocksource_init(rate, base);
+		rc = integrator_clocksource_init(rate, base);
+		goto out;
+	}
 
 	if (node == sec_node) {
 		/* The secondary timer will drive the clock event */
 		irq = irq_of_parse_and_map(node, 0);
-		return integrator_clockevent_init(rate, base, irq);
+		rc = integrator_clockevent_init(rate, base, irq);
+		goto out;
 	}
 
 	pr_info("Timer @%p unused\n", base);
 	clk_disable_unprepare(clk);
+out:
+	of_node_put(sec_node);
+out_put_pri_node:
+	of_node_put(pri_node);
 
-	return 0;
+	return rc;
 }
 
 TIMER_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
-- 
2.17.0

Re: [PATCH] clocksource/drivers/integrator-ap: add missing of_node_put()

[Frank Lee]

On Thu, Nov 22, 2018 at 11:23 PM Yangtao Li <tiny.windzz@gmail.com> wrote:
>
> of_find_node_by_path() acquires a reference to the node
> returned by it and that reference needs to be dropped by its caller.
> integrator_ap_timer_init_of() doesn't do that, so fix it.
>
> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> ---
>  drivers/clocksource/timer-integrator-ap.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
> index 76e526f58620..1f04069470bb 100644
> --- a/drivers/clocksource/timer-integrator-ap.c
> +++ b/drivers/clocksource/timer-integrator-ap.c
> @@ -177,7 +177,7 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
>  {
>         const char *path;
>         void __iomem *base;
> -       int err;
> +       int err,rc = 0;
>         int irq;
>         struct clk *clk;
>         unsigned long rate;
> @@ -210,26 +210,34 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
>                                 "arm,timer-secondary", &path);
>         if (err) {
>                 pr_warn("Failed to read property\n");
> -               return err;
> +               rc = err;
> +               goto out_put_pri_node;
>         }
>
>
>         sec_node = of_find_node_by_path(path);
>
> -       if (node == pri_node)
> +       if (node == pri_node){
>                 /* The primary timer lacks IRQ, use as clocksource */
> -               return integrator_clocksource_init(rate, base);
> +               rc = integrator_clocksource_init(rate, base);
> +               goto out;
> +       }
>
>         if (node == sec_node) {
>                 /* The secondary timer will drive the clock event */
>                 irq = irq_of_parse_and_map(node, 0);
> -               return integrator_clockevent_init(rate, base, irq);
> +               rc = integrator_clockevent_init(rate, base, irq);
> +               goto out;
>         }
>
>         pr_info("Timer @%p unused\n", base);
>         clk_disable_unprepare(clk);
> +out:
> +       of_node_put(sec_node);
> +out_put_pri_node:
> +       of_node_put(pri_node);
>
> -       return 0;
> +       return rc;
>  }
>
>  TIMER_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
> --
> 2.17.0
>
Hi Daniel：

How about this?

Thanks，
Yangtao

Re: [PATCH] clocksource/drivers/integrator-ap: add missing of_node_put()

[Daniel Lezcano]

On 24/11/2018 15:58, Frank Lee wrote:
> On Thu, Nov 22, 2018 at 11:23 PM Yangtao Li <tiny.windzz@gmail.com> wrote:
>>
>> of_find_node_by_path() acquires a reference to the node
>> returned by it and that reference needs to be dropped by its caller.
>> integrator_ap_timer_init_of() doesn't do that, so fix it.
>>
>> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
>> ---
>>  drivers/clocksource/timer-integrator-ap.c | 20 ++++++++++++++------
>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
>> index 76e526f58620..1f04069470bb 100644
>> --- a/drivers/clocksource/timer-integrator-ap.c
>> +++ b/drivers/clocksource/timer-integrator-ap.c
>> @@ -177,7 +177,7 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
>>  {
>>         const char *path;
>>         void __iomem *base;
>> -       int err;
>> +       int err,rc = 0;
>>         int irq;
>>         struct clk *clk;
>>         unsigned long rate;
>> @@ -210,26 +210,34 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
>>                                 "arm,timer-secondary", &path);
>>         if (err) {
>>                 pr_warn("Failed to read property\n");
>> -               return err;
>> +               rc = err;
>> +               goto out_put_pri_node;
>>         }
>>
>>
>>         sec_node = of_find_node_by_path(path);
>>
>> -       if (node == pri_node)
>> +       if (node == pri_node){
>>                 /* The primary timer lacks IRQ, use as clocksource */
>> -               return integrator_clocksource_init(rate, base);
>> +               rc = integrator_clocksource_init(rate, base);
>> +               goto out;
>> +       }
>>
>>         if (node == sec_node) {
>>                 /* The secondary timer will drive the clock event */
>>                 irq = irq_of_parse_and_map(node, 0);
>> -               return integrator_clockevent_init(rate, base, irq);
>> +               rc = integrator_clockevent_init(rate, base, irq);
>> +               goto out;
>>         }
>>
>>         pr_info("Timer @%p unused\n", base);
>>         clk_disable_unprepare(clk);
>> +out:
>> +       of_node_put(sec_node);
>> +out_put_pri_node:
>> +       of_node_put(pri_node);
>>
>> -       return 0;
>> +       return rc;
>>  }
>>
>>  TIMER_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
>> --
>> 2.17.0
>>
> Hi Daniel：
> 
> How about this?

Hi,

I think there is a simpler fix. The pri_node and the sec_node are used
as an identifier to compare against the current node, we can directly
drop the refcount after getting the node from path as it is not used as
pointer. In addition, a single variable is needed, so we end up with a
fix like that.

	alias_node = of_find_node_by_path(path);
	of_node_put(alias_node);
	if (node == alias_node)
		return integrator_clocksource_init(rate, base);



> 
> Thanks，
> Yangtao
> 


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Re: [PATCH] clocksource/drivers/integrator-ap: add missing of_node_put()

[Frank Lee]

On Sun, Nov 25, 2018 at 3:49 AM Daniel Lezcano
<daniel.lezcano@linaro.org> wrote:
>
> On 24/11/2018 15:58, Frank Lee wrote:
> > On Thu, Nov 22, 2018 at 11:23 PM Yangtao Li <tiny.windzz@gmail.com> wrote:
> >>
> >> of_find_node_by_path() acquires a reference to the node
> >> returned by it and that reference needs to be dropped by its caller.
> >> integrator_ap_timer_init_of() doesn't do that, so fix it.
> >>
> >> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> >> ---
> >>  drivers/clocksource/timer-integrator-ap.c | 20 ++++++++++++++------
> >>  1 file changed, 14 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
> >> index 76e526f58620..1f04069470bb 100644
> >> --- a/drivers/clocksource/timer-integrator-ap.c
> >> +++ b/drivers/clocksource/timer-integrator-ap.c
> >> @@ -177,7 +177,7 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
> >>  {
> >>         const char *path;
> >>         void __iomem *base;
> >> -       int err;
> >> +       int err,rc = 0;
> >>         int irq;
> >>         struct clk *clk;
> >>         unsigned long rate;
> >> @@ -210,26 +210,34 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
> >>                                 "arm,timer-secondary", &path);
> >>         if (err) {
> >>                 pr_warn("Failed to read property\n");
> >> -               return err;
> >> +               rc = err;
> >> +               goto out_put_pri_node;
> >>         }
> >>
> >>
> >>         sec_node = of_find_node_by_path(path);
> >>
> >> -       if (node == pri_node)
> >> +       if (node == pri_node){
> >>                 /* The primary timer lacks IRQ, use as clocksource */
> >> -               return integrator_clocksource_init(rate, base);
> >> +               rc = integrator_clocksource_init(rate, base);
> >> +               goto out;
> >> +       }
> >>
> >>         if (node == sec_node) {
> >>                 /* The secondary timer will drive the clock event */
> >>                 irq = irq_of_parse_and_map(node, 0);
> >> -               return integrator_clockevent_init(rate, base, irq);
> >> +               rc = integrator_clockevent_init(rate, base, irq);
> >> +               goto out;
> >>         }
> >>
> >>         pr_info("Timer @%p unused\n", base);
> >>         clk_disable_unprepare(clk);
> >> +out:
> >> +       of_node_put(sec_node);
> >> +out_put_pri_node:
> >> +       of_node_put(pri_node);
> >>
> >> -       return 0;
> >> +       return rc;
> >>  }
> >>
> >>  TIMER_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
> >> --
> >> 2.17.0
> >>
> > Hi Daniel：
> >
> > How about this?
>
> Hi,
>
> I think there is a simpler fix. The pri_node and the sec_node are used
> as an identifier to compare against the current node, we can directly
> drop the refcount after getting the node from path as it is not used as
> pointer. In addition, a single variable is needed, so we end up with a
> fix like that.
>
>         alias_node = of_find_node_by_path(path);
>         of_node_put(alias_node);
>         if (node == alias_node)
>                 return integrator_clocksource_init(rate, base);

Daniel,

OK,I will simplify it like you said.Although I think of_node_put
should be called
after we don't use node.

MBR，
Yangtao
>
>
>
> >
> > Thanks，
> > Yangtao
> >
>
>
> --
>  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>
> Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
>

Re: [PATCH] clocksource/drivers/integrator-ap: add missing of_node_put()

[Daniel Lezcano]

On 25/11/2018 05:25, Frank Lee wrote:
> On Sun, Nov 25, 2018 at 3:49 AM Daniel Lezcano
> <daniel.lezcano@linaro.org> wrote:
>>
>> On 24/11/2018 15:58, Frank Lee wrote:
>>> On Thu, Nov 22, 2018 at 11:23 PM Yangtao Li <tiny.windzz@gmail.com> wrote:
>>>>
>>>> of_find_node_by_path() acquires a reference to the node
>>>> returned by it and that reference needs to be dropped by its caller.
>>>> integrator_ap_timer_init_of() doesn't do that, so fix it.
>>>>
>>>> Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
>>>> ---
>>>>  drivers/clocksource/timer-integrator-ap.c | 20 ++++++++++++++------
>>>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/clocksource/timer-integrator-ap.c b/drivers/clocksource/timer-integrator-ap.c
>>>> index 76e526f58620..1f04069470bb 100644
>>>> --- a/drivers/clocksource/timer-integrator-ap.c
>>>> +++ b/drivers/clocksource/timer-integrator-ap.c
>>>> @@ -177,7 +177,7 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
>>>>  {
>>>>         const char *path;
>>>>         void __iomem *base;
>>>> -       int err;
>>>> +       int err,rc = 0;
>>>>         int irq;
>>>>         struct clk *clk;
>>>>         unsigned long rate;
>>>> @@ -210,26 +210,34 @@ static int __init integrator_ap_timer_init_of(struct device_node *node)
>>>>                                 "arm,timer-secondary", &path);
>>>>         if (err) {
>>>>                 pr_warn("Failed to read property\n");
>>>> -               return err;
>>>> +               rc = err;
>>>> +               goto out_put_pri_node;
>>>>         }
>>>>
>>>>
>>>>         sec_node = of_find_node_by_path(path);
>>>>
>>>> -       if (node == pri_node)
>>>> +       if (node == pri_node){
>>>>                 /* The primary timer lacks IRQ, use as clocksource */
>>>> -               return integrator_clocksource_init(rate, base);
>>>> +               rc = integrator_clocksource_init(rate, base);
>>>> +               goto out;
>>>> +       }
>>>>
>>>>         if (node == sec_node) {
>>>>                 /* The secondary timer will drive the clock event */
>>>>                 irq = irq_of_parse_and_map(node, 0);
>>>> -               return integrator_clockevent_init(rate, base, irq);
>>>> +               rc = integrator_clockevent_init(rate, base, irq);
>>>> +               goto out;
>>>>         }
>>>>
>>>>         pr_info("Timer @%p unused\n", base);
>>>>         clk_disable_unprepare(clk);
>>>> +out:
>>>> +       of_node_put(sec_node);
>>>> +out_put_pri_node:
>>>> +       of_node_put(pri_node);
>>>>
>>>> -       return 0;
>>>> +       return rc;
>>>>  }
>>>>
>>>>  TIMER_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",
>>>> --
>>>> 2.17.0
>>>>
>>> Hi Daniel：
>>>
>>> How about this?
>>
>> Hi,
>>
>> I think there is a simpler fix. The pri_node and the sec_node are used
>> as an identifier to compare against the current node, we can directly
>> drop the refcount after getting the node from path as it is not used as
>> pointer. In addition, a single variable is needed, so we end up with a
>> fix like that.
>>
>>         alias_node = of_find_node_by_path(path);
>>         of_node_put(alias_node);
>>         if (node == alias_node)
>>                 return integrator_clocksource_init(rate, base);
> 
> Daniel,
> 
> OK,I will simplify it like you said.Although I think of_node_put
> should be called
> after we don't use node.

Except I'm missing something, we don't use the alias_node at any time.
The node itself has already a refcount which gives us the guarantee it
is valid.

I agree it can appear a bit strange to put the node right after getting
it but in our case the alias_node is used as an ID, not a pointer, so it
is fine.




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