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Date:   Mon, 19 Jun 2023 00:33:56 +0300
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Subject: Re: [PATCH v2 2/2] misc: sram: Generate unique names for subpools
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To:     Linus Walleij <linus.walleij@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Rob Herring <robh@kernel.org>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230417-ux500-sram-v2-0-6e62ad551faa@linaro.org>
 <20230417-ux500-sram-v2-2-6e62ad551faa@linaro.org>
From:   Dmitry Osipenko <digetx@gmail.com>
In-Reply-To: <20230417-ux500-sram-v2-2-6e62ad551faa@linaro.org>
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21.04.2023 00:17, Linus Walleij пишет:
> The current code will, if we do not specify unique labels
> for the SRAM subnodes, fail to register several nodes named
> the same.
> 
> Example:
> 
> sram@40020000 {
>   (...)
>   sram@0 {
>     (...)
>   };
>   sram@1000 {
>     (...)
>   };
> };
> 
> Since the child->name in both cases will be "sram" the
> gen_pool_create() will fail because the name is not unique.
> 
> Use dev_name() for the device as this will have bus ID
> set to the fully translated address for the node, and that
> will always be unique.
> 
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - Stop complicating things and just use dev_name()
> ---
>  drivers/misc/sram.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
> index f0e7f02605eb..f80c3adddf0b 100644
> --- a/drivers/misc/sram.c
> +++ b/drivers/misc/sram.c
> @@ -240,10 +240,11 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
>  				goto err_chunks;
>  			}
>  			if (!label)
> -				label = child->name;
> -
> -			block->label = devm_kstrdup(sram->dev,
> -						    label, GFP_KERNEL);
> +				block->label = devm_kasprintf(sram->dev, GFP_KERNEL,
> +							      "%s", dev_name(sram->dev));

This broke device-trees that have no label property. The SRAM DT binding
says:

"
label:
description:
	The name for the reserved partition, if omitted, the label is taken
	from the node name excluding the unit address.
"

Not sure whether breakage was on purpose, otherwise doc needs to be
updated or there should be explicit check for the duplicated node names.

Secondly, AFAICS, the dev_name(sram->dev) is the name of the parent SRAM
device and not of the children sub-nodes, hence it's now always the same
dev_name(sram->dev) for all sub-nodes.