2017-11-13 04:09:46

by Phil Reid

[permalink] [raw]
Subject: Re: [PATCH] net: dsa: lan9303: correctly check return value of devm_gpiod_get_optional

On 12/11/2017 23:38, Pan Bian wrote:
> Function devm_gpiod_get_optional() returns an ERR_PTR on failure. Its
> return value should not be validated by a NULL check. Instead, use IS_ERR.
>
> Signed-off-by: Pan Bian <[email protected]>
> ---
> drivers/net/dsa/lan9303-core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
> index b471413..6d3fc8f 100644
> --- a/drivers/net/dsa/lan9303-core.c
> +++ b/drivers/net/dsa/lan9303-core.c
> @@ -828,7 +828,7 @@ static void lan9303_probe_reset_gpio(struct lan9303 *chip,
> chip->reset_gpio = devm_gpiod_get_optional(chip->dev, "reset",
> GPIOD_OUT_LOW);
>
> - if (!chip->reset_gpio) {
> + if (IS_ERR(chip->reset_gpio)) {
> dev_dbg(chip->dev, "No reset GPIO defined\n");
> return;
> }
>
Should not an error actually report the error and error out (ie fail probe).
But a null is the optional return and ok. (ie when -ENOENT return from sub gpiod_get call).

IS_ERR should be a separate condition check I think.

related lan9303_handle_reset() always returns 0.

lan9303_probe checks lan9303_handle_reset() return value.

Probably should be checking lan9303_probe_reset_gpio() instead.

--
Regards
Phil Reid

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