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Date:   Mon, 31 Jul 2023 17:45:06 +0200
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Daniel Golle <daniel@makrotopia.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] nvmem: core: append offset to cell name in sysfs
Message-ID: <20230731174506.00368411@xps-13>
In-Reply-To: <ZLaZ7fzUSsa0Igx1@makrotopia.org>
References: <ZLaZ7fzUSsa0Igx1@makrotopia.org>
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Hi Daniel,

daniel@makrotopia.org wrote on Tue, 18 Jul 2023 14:55:57 +0100:

> The device tree node names are not required to be unique. Append the
> offset to the name to make cell nodes with identical names become
> accessible via sysfs and avoid kernel stackdump caused by
> sysfs: cannot create duplicate filename '...'
>=20
> Fixes: 757f8b3835c9 ("nvmem: core: Expose cells through sysfs")
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> ---
>  drivers/nvmem/core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>=20
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index 70e951088826d..90fe9dc30f8ba 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -480,7 +480,9 @@ static int nvmem_populate_sysfs_cells(struct nvmem_de=
vice *nvmem)
>  	/* Initialize each attribute to take the name and size of the cell */
>  	list_for_each_entry(entry, &nvmem->cells, node) {
>  		sysfs_bin_attr_init(&attrs[i]);
> -		attrs[i].attr.name =3D devm_kstrdup(&nvmem->dev, entry->name, GFP_KERN=
EL);
> +		attrs[i].attr.name =3D devm_kasprintf(&nvmem->dev, GFP_KERNEL,
> +						    "%s@%d", entry->name,
> +						    entry->offset);

Shouldn't we use %s@%x instead to match the DT descriptions?

>  		attrs[i].attr.mode =3D 0444;
>  		attrs[i].size =3D entry->bytes;
>  		attrs[i].read =3D &nvmem_cell_attr_read;

I plan another version of the series which triggered these patches, if
you don't mind I will squash patch 1 into my patches and pick this one
as a preparation change (likely with the above fix if you agree and
without the Fixes tag).

Thanks,
Miqu=C3=A8l