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From:   Rob Herring <robh+dt@kernel.org>
Date:   Thu, 13 Jul 2023 10:45:24 -0600
Message-ID: <CAL_JsqKSnhvgDfXA46v_CzFn1q1U_Lr7N=JA8bMYMrPAgENOWA@mail.gmail.com>
Subject: Re: [PATCH V2] of: property: fw_devlink: fixup return value check of
 strcmp_suffix in parse_gpios
To:     Li Chen <me@linux.beauty>
Cc:     Frank Rowand <frowand.list@gmail.com>,
        devicetree <devicetree@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Thu, Jul 13, 2023 at 4:47=E2=80=AFAM Li Chen <me@linux.beauty> wrote:
>
> This commit addresses an issue where enabling fw_devlink=3Don was causing
> a PCIe malfunction, resulting in endpoints missing.
> After thorough investigation, it was determined that the root cause was
> an incorrect usage of strcmp_suffix in parse_gpios.
>
> Fixes: d473d32c2fba ("of: property: fw_devlink: do not link ".*,nr-gpios"=
")
> Signed-off-by: Li Chen <lchen@ambarella.com>
> Cc: stable@vger.kernel.org
> ---
> changes:
> v1->v2: add Cc stable
>
>  drivers/of/property.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index ddc75cd50825..261eb8f3be08 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1272,7 +1272,7 @@ DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
>  static struct device_node *parse_gpios(struct device_node *np,
>                                        const char *prop_name, int index)
>  {
> -       if (!strcmp_suffix(prop_name, ",nr-gpios"))
> +       if (strcmp_suffix(prop_name, ",nr-gpios"))

strcmp returns 0 when there is a match. When we match ",nr-gpios", we
want to bail out. The existing code was correct. Your patch just
disables fw_devlink for all GPIO dependencies.

Rob