At 2022-06-17 07:37:06, "Michael Ellerman" <m...@ellerman.id.au> wrote:
>Christophe JAILLET <christophe.jail...@wanadoo.fr> writes:
>> Le 16/06/2022 à 17:19, Liang He a écrit :
>>> In gpio_halt_probe(), of_find_matching_node() will return a node pointer
>>> with
>>> refcount incremented. We should use of_node_put() in each fail path or when
>>> it
>>> is not used anymore.
>>>
>>> Signed-off-by: Liang He <win...@126.com>
>>> ---
>>> changelog:
>>>
>>> v2: use goto-label patch style advised by Christophe.
>>> v1: add of_node_put() before each exit.
>>>
>>> arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++--------
>>> 1 file changed, 18 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c
>>> b/arch/powerpc/platforms/85xx/sgy_cts1000.c
>>> index 98ae64075193..e280f963d88c 100644
>>> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c
>>> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c
>>> @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev)
>...
>>> @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device
>>> *pdev)
>>>
>>> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d"
>>> " irq).\n", gpio, trigger, irq);
>>> + ret = 0;
>>>
>>> - return 0;
>>> +err_put:
>>> + of_node_put(halt_node);
>>> + halt_node = NULL;
>>
>> Hi,
>> so now we set 'halt_node' to NULL even in the normal case.
>> This is really spurious.
>>
>> Look at gpio_halt_cb(), but I think that this is just wrong and badly
>> breaks this driver.
>
>I agree, thanks for reviewing.
>
>I think the cleanest solution is to use a local variable for the node in
>the body of gpio_halt_probe(), and only assign to halt_node once all the
>checks have passed.
>
>So something like:
>
> struct device_node *child_node;
>
> child_node = of_find_matching_node(node, child_match);
> ...
>
> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d"
> " irq).\n", gpio, trigger, irq);
> ret = 0;
> halt_node = of_node_get(child_node);
>
>out_put:
> of_node_put(child_node);
>
> return ret;
>}
>
>
>cheers
Hi, Michael and Christophe,
I am writing the new patch based on Michael's advice. However, I wonder if
there is
any place to call of_node_put(halt_node)? As I do not exactly know if
gpio_halt_remove()
or anyother place can correctly release this global reference？
If not, it is correct that I add a of_node_put(halt_node) in
gpio_halt_remove(), right?
Thanks and wait for your replies.
Liang
