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Date:   Tue, 16 Mar 2021 14:21:13 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Voon Weifeng <weifeng.voon@intel.com>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jose Abreu <joabreu@synopsys.com>,
        Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org,
        Ong Boon Leong <boon.leong.ong@intel.com>,
        Wong Vee Khee <vee.khee.wong@intel.com>
Subject: Re: [RESEND v1 net-next 2/5] net: stmmac: make stmmac_interrupt()
 function more friendly to MSI
Message-ID: <20210316142113.40fd721f@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
In-Reply-To: <20210316121823.18659-3-weifeng.voon@intel.com>
References: <20210316121823.18659-1-weifeng.voon@intel.com>
        <20210316121823.18659-3-weifeng.voon@intel.com>
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On Tue, 16 Mar 2021 20:18:20 +0800 Voon Weifeng wrote:
> +	if (unlikely(!dev)) {
> +		netdev_err(priv->dev, "%s: invalid dev pointer\n", __func__);
> +		return IRQ_NONE;
> +	}

Where did this check come from? Please avoid defensive programming 
in the kernel unless you can point out how the condition can arise
legitimately.