linux-kernel - Re: [PATCH] mips: lantiq: Add missing of_node

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Message-ID: <deac1d48-493c-c637-c00c-d6f09f56b074@kernel.org>
Date:   Wed, 22 Jun 2022 11:02:38 +0200
From:   Krzysztof Kozlowski <krzk@...nel.org>
To:     Liang He <windhl@....com>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>
Cc:     john@...ozen.org, linux-mips@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mips: lantiq: Add missing of_node_put() in irq.c

On 21/06/2022 17:32, Liang He wrote:
> 
> 
> At 2022-06-21 23:21:19, "Thomas Bogendoerfer" <tsbogend@...ha.franken.de> wrote:
>> On Wed, Jun 15, 2022 at 11:33:39PM +0800, Liang He wrote:
>>> In icu_of_init(), of_find_compatible_node() will return a node
>>> pointer with refcount incremented. We should use of_node_put()
>>> when it is not used anymore.
>>>
>>> Signed-off-by: Liang He <windhl@....com>
>>> ---
>>>  arch/mips/lantiq/irq.c | 6 ++++++
>>>  1 file changed, 6 insertions(+)
>>>
>>> diff --git a/arch/mips/lantiq/irq.c b/arch/mips/lantiq/irq.c
>>> index b732495f138a..62f1b20a2169 100644
>>> --- a/arch/mips/lantiq/irq.c
>>> +++ b/arch/mips/lantiq/irq.c
>>> @@ -396,6 +396,9 @@ int __init icu_of_init(struct device_node *node, struct device_node *parent)
>>>  
>>>  		ret = of_property_read_u32_array(eiu_node, "lantiq,eiu-irqs",
>>>  						ltq_eiu_irq, exin_avail);
>>> +						
>>
>> trailing whitespaces
>>
>>> +		of_node_put(eiu_node);
>>> +						
>>
>> trailing whitespaces
>>
>>>  		if (ret)
>>>  			panic("failed to load external irq resources");
>>>  
>>> @@ -409,6 +412,9 @@ int __init icu_of_init(struct device_node *node, struct device_node *parent)
>>>  			panic("Failed to remap eiu memory");
>>>  	}
>>>  
>>> +	/* if eiu_node&of_address_to_resource */
>>> +	of_node_put(eiu_node);
>>> +
>>
>> if I'm not mistaken you are freeing the taken reference twice. Shouldn't
>> it work by only adding the last of_node_put() ?
>>
>> Thomas.
> 
> Hi, Thomas.
> 
> Thanks very much for your effort to review and apply my patches.
> 
> You are right, this patch is wrong and only the last put is needed.
> 
> I will send a new patch: removing trailing whitspace and the first put.
> 
> Thans again.

Thomas,

Before applying the patch please check it carefully. Previous evidence
[1][2] suggests that not it was not even compiled.



[1] https://lore.kernel.org/all/202206221602.odN70SHs-lkp@intel.com/

[2]
https://lore.kernel.org/all/16f9a971.44e5.1817068ee3c.Coremail.windhl@126.com/


Best regards,
Krzysztof