Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <20e56bff-b456-3301-0594-dac917416a92@gmail.com>
Date:   Sat, 16 Apr 2022 12:38:09 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.8.0
Subject: Re: [PATCH net-next v4 05/18] net: dsa: mv88e6xxx: remove redundant
 check in mv88e6xxx_port_vlan()
Content-Language: en-US
To:     Jakob Koschel <jakobkoschel@gmail.com>,
        "David S. Miller" <davem@davemloft.net>
Cc:     Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Lars Povlsen <lars.povlsen@microchip.com>,
        Steen Hegelund <Steen.Hegelund@microchip.com>,
        UNGLinuxDriver@microchip.com, Ariel Elior <aelior@marvell.com>,
        Manish Chopra <manishc@marvell.com>,
        Edward Cree <ecree.xilinx@gmail.com>,
        Martin Habets <habetsm.xilinx@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Jiri Pirko <jiri@resnulli.us>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Casper Andersson <casper.casan@gmail.com>,
        Bjarni Jonasson <bjarni.jonasson@microchip.com>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Arnd Bergmann <arnd@arndb.de>,
        Colin Ian King <colin.king@intel.com>,
        Eric Dumazet <edumazet@google.com>,
        Xu Wang <vulab@iscas.ac.cn>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, bpf@vger.kernel.org,
        Mike Rapoport <rppt@kernel.org>,
        Brian Johannesmeyer <bjohannesmeyer@gmail.com>,
        Cristiano Giuffrida <c.giuffrida@vu.nl>,
        "Bos, H.J." <h.j.bos@vu.nl>,
        Vladimir Oltean <vladimir.oltean@nxp.com>
References: <20220415122947.2754662-1-jakobkoschel@gmail.com>
 <20220415122947.2754662-6-jakobkoschel@gmail.com>
From:   Florian Fainelli <f.fainelli@gmail.com>
In-Reply-To: <20220415122947.2754662-6-jakobkoschel@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 4/15/2022 5:29 AM, Jakob Koschel wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
> 
> We know that "dev > dst->last_switch" in the "else" block.
> In other words, that "dev - dst->last_switch" is > 0.
> 
> dsa_port_bridge_num_get(dp) can be 0, but the check
> "if (bridge_num + dst->last_switch != dev) continue", rewritten as
> "if (bridge_num != dev - dst->last_switch) continue", aka
> "if (bridge_num != something which cannot be 0) continue",
> makes it redundant to have the extra "if (!bridge_num) continue" logic,
> since a bridge_num of zero would have been skipped anyway.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian