linux-kernel - Re: [PATCH] dt: dt-extract-compatibles: Extract compatibles from function parameters

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Message-ID: <80c61f1d-5bae-4288-b868-b25d48d679a6@notapiano>
Date: Wed, 4 Sep 2024 16:42:34 -0400
From: Nícolas F. R. A. Prado <nfraprado@...labora.com>
To: "Rob Herring (Arm)" <robh@...nel.org>
Cc: Saravana Kannan <saravanak@...gle.com>, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] dt: dt-extract-compatibles: Extract compatibles from
 function parameters

On Tue, Sep 03, 2024 at 03:07:52PM -0500, Rob Herring (Arm) wrote:
> Various DT and fwnode functions take a compatible string as a parameter.
> These are often used in cases which don't have a driver, so they've been
> missed.
> 
> The additional checks add about 400 more undocumented compatible
> strings.
> 
> Cc: Nícolas F. R. A. Prado <nfraprado@...labora.com>
> Signed-off-by: Rob Herring (Arm) <robh@...nel.org>
> ---
>  scripts/dtc/dt-extract-compatibles | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/scripts/dtc/dt-extract-compatibles b/scripts/dtc/dt-extract-compatibles
> index 5ffb2364409b..13ea66d49e6c 100755
> --- a/scripts/dtc/dt-extract-compatibles
> +++ b/scripts/dtc/dt-extract-compatibles
> @@ -46,6 +46,15 @@ def parse_of_match_table(data):
>  	return match_table_list
>  
>  
> +def parse_of_functions(data, func_name):
> +	""" Find all (device|machine)_is_compatible() arguments """

This comment looks outdated.

"Find all compatibles in the last argument of a given function"?

> +	match_table_list = []

A better name would be compat_list like in the other functions that return lists
of compatibles.

> +	for m in re.finditer(rf'{func_name}\(([a-zA-Z0-9_>\(\)"\-]+,\s)*"([a-zA-Z0-9_,-]+)"\)', data):
> +		match_table_list.append(m[2])
> +
> +	return match_table_list
> +
> +
>  def parse_compatibles(file, compat_ignore_list):
>  	with open(file, 'r', encoding='utf-8') as f:
>  		data = f.read().replace('\n', '')
> @@ -60,6 +69,10 @@ def parse_compatibles(file, compat_ignore_list):
>  	else:
>  		compat_list = parse_of_declare_macros(data)
>  		compat_list += parse_of_device_id(data)
> +		compat_list += parse_of_functions(data, "_is_compatible")

This pattern seems very broad and bound to generate false-positives. That said,
I glanced over the results and didn't see any string clearly wrong, so I guess
it's fine. There were a couple suspicious strings like "B5221" but they were
indeed used in the of functions, so it's working correctly.

> +		compat_list += parse_of_functions(data, "of_find_compatible_node")
> +		compat_list += parse_of_functions(data, "for_each_compatible_node")
> +		compat_list += parse_of_functions(data, "of_get_compatible_child")
>  
>  	return compat_list
>  
> -- 
> 2.45.2
> 

Reviewed-by: Nícolas F. R. A. Prado <nfraprado@...labora.com>

On a related note, I'm wondering if you haven't had time to see
https://lore.kernel.org/all/20240729-dt-kselftest-parent-disabled-v2-1-d7a001c4930d@collabora.com
or if that patch didn't make it to you somehow.

Thanks,
Nícolas