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Subject: Re: [PATCH][next] net: usb: asix: ax88772: Fix less than zero
 comparison of a u16
To:     Colin King <colin.king@canonical.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Oleksij Rempel <linux@rempel-privat.de>,
        linux-usb@vger.kernel.org, netdev@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20210608145823.159467-1-colin.king@canonical.com>
From:   Sergei Shtylyov <sergei.shtylyov@gmail.com>
Organization: Brain-dead Software
Message-ID: <5ac017f5-b8cc-6177-888a-318681b36da3@gmail.com>
Date:   Wed, 9 Jun 2021 12:51:33 +0300
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On 08.06.2021 17:58, Colin King wrote:

> From: Colin Ian King <colin.king@canonical.com>
> 
> The comparison of the u16 priv->phy_addr < 0 is always false because
> phy_addr is unsigned. Fix this by assigning the return from the call
> to function asix_read_phy_addr to int ret and using this for the
> less than zero error check comparison.
> 
> Addresses-Coverity: ("Unsigned compared against 0")
> Fixes: e532a096be0e ("net: usb: asix: ax88772: add phylib support")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   drivers/net/usb/asix_devices.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
> index 57dafb3262d9..211c5a87eb15 100644
> --- a/drivers/net/usb/asix_devices.c
> +++ b/drivers/net/usb/asix_devices.c
> @@ -704,9 +704,10 @@ static int ax88772_init_phy(struct usbnet *dev)
>   	struct asix_common_private *priv = dev->driver_priv;
>   	int ret;
>   
> -	priv->phy_addr = asix_read_phy_addr(dev, true);
> -	if (priv->phy_addr < 0)
> +	ret = asix_read_phy_addr(dev, true);
> +	if (ret < 0)
>   		return priv->phy_addr;

    It's not yet assigned at this point, should be:

		return ret;

> +	priv->phy_addr = ret;

    Assigned only here. :-)

>   	snprintf(priv->phy_name, sizeof(priv->phy_name), PHY_ID_FMT,
>   		 priv->mdio->id, priv->phy_addr);

MBR, Sergei