netdev - Re: [PATCH -next] net: dsa: Simplify with scoped for each OF child loop

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Message-ID: <0d2ac86a-dc01-362a-e444-e72359d1f0b7@huawei.com>
Date: Fri, 23 Aug 2024 14:35:04 +0800
From: Jinjie Ruan <ruanjinjie@...wei.com>
To: Jakub Kicinski <kuba@...nel.org>
CC: <andrew@...n.ch>, <f.fainelli@...il.com>, <olteanv@...il.com>,
	<davem@...emloft.net>, <edumazet@...gle.com>, <pabeni@...hat.com>,
	<netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH -next] net: dsa: Simplify with scoped for each OF child
 loop



On 2024/8/22 22:51, Jakub Kicinski wrote:
> On Thu, 22 Aug 2024 10:07:25 +0800 Jinjie Ruan wrote:
>> On 2024/8/22 8:18, Jakub Kicinski wrote:
>>> On Tue, 20 Aug 2024 14:58:04 +0800 Jinjie Ruan wrote:  
>>>> Use scoped for_each_available_child_of_node_scoped() when iterating over
>>>> device nodes to make code a bit simpler.  
>>>
>>> Could you add more info here that confirms this works with gotos?
>>> I don't recall the details but I thought sometimes the scoped
>>> constructs don't do well with gotos. I checked 5 random uses
>>> of this loop and 4 of them didn't have gotos.  
>>
>> Hi, Jakub
>>
>> From what I understand, for_each_available_child_of_node_scoped() is not
>> related to gotos, it only let the iterating child node self-declared and
>> automatic release, so the of_node_put(iterating_child_node) can be removed.
> 
> Could you either test it or disasm the code to double check, please?

Hi, Jakub, I test it with a fake device node on QEMU with a simple
example using for_each_available_child_of_node_scoped() and goto out of
the scope of for_each_available_child_of_node_scoped(), the
of_node_put(child) has been called successfully.