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Message-ID: <8d4b8cc3-8433-24f9-1fc5-12d71e640952@gmail.com>
Date:   Tue, 31 May 2022 16:43:18 -0400
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Subject: Re: [PATCH] scripts: dtc: fix a false alarm for
 node_name_chars_strict
Content-Language: en-US
To:     Qun-Wei Lin <qun-wei.lin@mediatek.com>, robh+dt@kernel.org,
        matthias.bgg@gmail.com
Cc:     devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, casper.li@mediatek.com,
        chinwen.chang@mediatek.com, kuan-ying.lee@mediatek.com
References: <20220531053358.19003-1-qun-wei.lin@mediatek.com>
From:   Frank Rowand <frowand.list@gmail.com>
In-Reply-To: <20220531053358.19003-1-qun-wei.lin@mediatek.com>
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On 5/31/22 01:33, Qun-Wei Lin wrote:
> The function check_node_name_chars_strict issues a false alarm when
> compiling an overlay dts.
> 
> /fragment@0/__overlay__: Character '_' not recommended in node name
> 
> This workaround will fix it by skip checking for node named __overlay__.

This is not a false alarm.

Do not special case node name "__overlay__".  This node name should never
occur in a modern overlay source file.

For details, see "Overlay Source Format" in the "Overlays" section of:
https://elinux.org/Device_Tree_Reference#Overlays

That paragraph also has a pointer to the correct format for overlay
source files, which is slides 29-34 of:
https://elinux.org/Device_Tree_Reference#Overlays

-Frank

> 
> Signed-off-by: Qun-Wei Lin <qun-wei.lin@mediatek.com>
> ---
>  scripts/dtc/checks.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/scripts/dtc/checks.c b/scripts/dtc/checks.c
> index 781ba1129a8e..6ef4f2cd67b9 100644
> --- a/scripts/dtc/checks.c
> +++ b/scripts/dtc/checks.c
> @@ -325,6 +325,11 @@ static void check_node_name_chars_strict(struct check *c, struct dt_info *dti,
>  {
>  	int n = strspn(node->name, c->data);
>  
> +	if (streq(node->name, "__overlay__")) {
> +		/* HACK: Overlay fragments are a special case */
> +		return;
> +	}
> +
>  	if (n < node->basenamelen)
>  		FAIL(c, dti, node, "Character '%c' not recommended in node name",
>  		     node->name[n]);