Subject: Re: [PATCH] software node: fix wrong node passed to find nargs_prop
To:     =?UTF-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= <clement.leger@bootlin.com>
Cc:     Andy Shevchenko <andy.shevchenko@gmail.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        "linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20211220210533.3578678-1-clement.leger@bootlin.com>
 <CAHp75Vf+F2L4EFmokRYD+-M9hSuz+SbiiWnqHvFZttRyfKS-mg@mail.gmail.com>
 <d9f5b201-2a00-799d-3a0f-7c9709d77102@gmail.com>
 <20211221104659.2f8af03a@fixe.home>
From:   Daniel Scally <djrscally@gmail.com>
Message-ID: <36e29eb4-c3ab-af60-5106-04b289a87128@gmail.com>
Date:   Tue, 21 Dec 2021 22:08:42 +0000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.14.0
MIME-Version: 1.0
In-Reply-To: <20211221104659.2f8af03a@fixe.home>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hello

On 21/12/2021 09:46, Clément Léger wrote:
> Le Mon, 20 Dec 2021 23:37:07 +0000,
> Daniel Scally <djrscally@gmail.com> a écrit :
> 
>> Thanks Andy
>>
>> On 20/12/2021 22:13, Andy Shevchenko wrote:
>>  [...]  
>>
>> I think this is right (it's not used in the ACPI version, and the OF
>> version is quite convoluted so a bit hard to follow)...but also I note
>> that none of the users of fwnode_property_get_reference_args() pass
>> anything to nargs_prop anyway...do we even need this?
> 
> Indeed, this is currently not used anywhere, nargs is always used
> instead of nargs_prop. The usage is meant to be (almost) the same as
> of_parse_phandle_with_args().
> 
> ie:
> 
>  ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
> 				  index, &args);
> 
> can be replaced by:
> 
>  ret = fwnode_property_get_reference_args(node, "resets",
> 					  "#reset-cells", 0 index,
> 					  &args);
> 
> I have some patches that uses that with software nodes and that will
> need this support.

Ok, in that case I think this is the right thing to do and you can have my:

Reviewed-by: Daniel Scally <djrscally@gmail.com>

Might be nice to transfer the function comment from
of_parse_phandle_with_args() to fwnode_property_get_reference_args(), as
that's nice and clear.

>>
>> Use the correct reference node in call to
>>>     property_entry_read_int_array() to retrieve the correct nargs value.
>>>
>>>     Fixes: b06184acf751 ("software node: Add
>>>     software_node_get_reference_args()")  
>>
>> I think this might have been introduced later...maybe 996b0830f95d1,
>> maybe e933bedd45099
> 
> From what I saw, it was already in the original commit adding this but
> I can be wrong.

You're right of course - sorry for the noise

>>
>>>     Signed-off-by: Clément Léger <clement.leger@bootlin.com
>>>     <mailto:clement.leger@bootlin.com>>
>>>     ---
>>>      drivers/base/swnode.c | 2 +-
>>>      1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>>     diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
>>>     index 4debcea4fb12..0a482212c7e8 100644
>>>     --- a/drivers/base/swnode.c
>>>     +++ b/drivers/base/swnode.c
>>>     @@ -529,7 +529,7 @@ software_node_get_reference_args(const struct
>>>     fwnode_handle *fwnode,
>>>                     return -ENOENT;
>>>
>>>             if (nargs_prop) {
>>>     -               error =
>>>     property_entry_read_int_array(swnode->node->properties,
>>>     +               error =
>>>     property_entry_read_int_array(ref->node->properties,
>>>                                                           nargs_prop,
>>>     sizeof(u32),
>>>                                                          
>>>     &nargs_prop_val, 1);
>>>                     if (error)
>>>     -- 
>>>     2.34.1
>>>
>>>
>>>
>>> -- 
>>> With Best Regards,
>>> Andy Shevchenko
>>>
>>>   
> 
> 
>