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Message-ID: <9440fe5e-6c93-0254-3846-334fac1f8c74@linaro.org>
Date:   Thu, 5 Jan 2023 17:15:06 +0000
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Subject: Re: [PATCH] nvmem: core: return -ENOENT if nvmem cell is not found
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To:     Michael Walle <michael@walle.cc>,
        Alexander Stein <alexander.stein@ew.tq-group.com>
Cc:     linux-kernel@vger.kernel.org,
        Miquel Raynal <miquel.raynal@bootlin.com>
References: <20230105135931.2743351-1-michael@walle.cc>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
In-Reply-To: <20230105135931.2743351-1-michael@walle.cc>
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On 05/01/2023 13:59, Michael Walle wrote:
> Prior to commit 3cb05fdbaed6 ("nvmem: core: add an index parameter to
> the cell") of_nvmem_cell_get() would return -ENOENT if the cell wasn't
> found. Particularly, if of_property_match_string() returned -EINVAL,
> that return code was passed as the index to of_parse_phandle(), which
> then detected it as invalid and returned NULL. That led to an return
> code of -ENOENT.
> 
> With the new code, the negative index will lead to an -EINVAL of
> of_parse_phandle_with_optional_args() which pass straight to the
> caller and break those who expect an -ENOENT.
> 
> Fix it by always returning -ENOENT.
> 
> Fixes: 3cb05fdbaed6 ("nvmem: core: add an index parameter to the cell")
> Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> 

Applied thanks,

--srini
> Alexander, could you give this another try? I've changed it slightly,
> so it's a better match with how the handling was before.
> 
> 
>   drivers/nvmem/core.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index 1b61c8bf0de4..cc885b602690 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -1343,7 +1343,7 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
>   						  "#nvmem-cell-cells",
>   						  index, &cell_spec);
>   	if (ret)
> -		return ERR_PTR(ret);
> +		return ERR_PTR(-ENOENT);
>   
>   	if (cell_spec.args_count > 1)
>   		return ERR_PTR(-EINVAL);