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Date:   Thu, 10 Sep 2020 12:29:12 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Luo Jiaxing <luojiaxing@huawei.com>
Cc:     <peppe.cavallaro@st.com>, <alexandre.torgue@st.com>,
        <joabreu@synopsys.com>, <davem@davemloft.net>,
        <mcoquelin.stm32@gmail.com>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linuxarm@huawei.com>
Subject: Re: [PATCH net-next] net: stmmac: Remove unused variable 'ret' at
 stmmac_rx_buf1_len()
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On Thu, 10 Sep 2020 10:42:45 +0800 Luo Jiaxing wrote:
> Fixes the following warning when using W=3D1 to build kernel:
>=20
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:3634:6: warning: variab=
le =E2=80=98ret=E2=80=99 set but not used [-Wunused-but-set-variable]
> int ret, coe =3D priv->hw->rx_csum;
>=20
> When digging stmmac_get_rx_header_len(), dwmac4_get_rx_header_len() and
> dwxgmac2_get_rx_header_len() return 0 by default. Therefore, ret do not
> need to check the error value and can be directly deleted.
>=20
> Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>=20
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/=
net/ethernet/stmicro/stmmac/stmmac_main.c
> index 89b2b34..7e95412 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3631,15 +3631,15 @@ static unsigned int stmmac_rx_buf1_len(struct stm=
mac_priv *priv,
>  				       struct dma_desc *p,
>  				       int status, unsigned int len)
>  {
> -	int ret, coe =3D priv->hw->rx_csum;
>  	unsigned int plen =3D 0, hlen =3D 0;
> +	int coe =3D priv->hw->rx_csum;
> =20
>  	/* Not first descriptor, buffer is always zero */
>  	if (priv->sph && len)
>  		return 0;
> =20
>  	/* First descriptor, get split header length */
> -	ret =3D stmmac_get_rx_header_len(priv, p, &hlen);
> +	stmmac_get_rx_header_len(priv, p, &hlen);

This function should return void if there never are any errors to
report.

>  	if (priv->sph && hlen) {
>  		priv->xstats.rx_split_hdr_pkt_n++;
>  		return hlen;