Re: [PATCH] nvmem: core: return -ENOENT if nvmem cell is not found

[Alexander Stein <alexander.stein@ew.tq-group.com>]

Am Donnerstag, 5. Januar 2023, 14:59:31 CET schrieb Michael Walle:
> 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>
> ---
> 
> 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);

Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>