linux-kernel - [PATCH net-next v3 05/18] net: dsa: mv88e6xxx: remove redundant check in mv88e6xxx_port

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Message-Id: <20220412121557.3553555-6-jakobkoschel@gmail.com>
Date:   Tue, 12 Apr 2022 14:15:44 +0200
From:   Jakob Koschel <jakobkoschel@...il.com>
To:     "David S. Miller" <davem@...emloft.net>
Cc:     Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Vladimir Oltean <olteanv@...il.com>,
        Lars Povlsen <lars.povlsen@...rochip.com>,
        Steen Hegelund <Steen.Hegelund@...rochip.com>,
        UNGLinuxDriver@...rochip.com, Ariel Elior <aelior@...vell.com>,
        Manish Chopra <manishc@...vell.com>,
        Edward Cree <ecree.xilinx@...il.com>,
        Martin Habets <habetsm.xilinx@...il.com>,
        Michael Ellerman <mpe@...erman.id.au>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Jiri Pirko <jiri@...nulli.us>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Martin KaFai Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        John Fastabend <john.fastabend@...il.com>,
        KP Singh <kpsingh@...nel.org>,
        Casper Andersson <casper.casan@...il.com>,
        Bjarni Jonasson <bjarni.jonasson@...rochip.com>,
        Jakob Koschel <jakobkoschel@...il.com>,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>,
        Michael Walle <michael@...le.cc>,
        Jason Gunthorpe <jgg@...pe.ca>,
        Colin Ian King <colin.king@...el.com>,
        Arnd Bergmann <arnd@...db.de>,
        Eric Dumazet <edumazet@...gle.com>,
        Di Zhu <zhudi21@...wei.com>, Xu Wang <vulab@...as.ac.cn>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linuxppc-dev@...ts.ozlabs.org, bpf@...r.kernel.org,
        Mike Rapoport <rppt@...nel.org>,
        "Brian Johannesmeyer" <bjohannesmeyer@...il.com>,
        Cristiano Giuffrida <c.giuffrida@...nl>,
        "Bos, H.J." <h.j.bos@...nl>,
        Vladimir Oltean <vladimir.oltean@....com>
Subject: [PATCH net-next v3 05/18] net: dsa: mv88e6xxx: remove redundant check in mv88e6xxx_port_vlan()

From: Vladimir Oltean <vladimir.oltean@....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@....com>
Signed-off-by: Jakob Koschel <jakobkoschel@...il.com>
---
 drivers/net/dsa/mv88e6xxx/chip.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 64f4fdd02902..b3aa0e5bc842 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -1404,9 +1404,6 @@ static u16 mv88e6xxx_port_vlan(struct mv88e6xxx_chip *chip, int dev, int port)
 		list_for_each_entry(dp, &dst->ports, list) {
 			unsigned int bridge_num = dsa_port_bridge_num_get(dp);
 
-			if (!bridge_num)
-				continue;
-
 			if (bridge_num + dst->last_switch != dev)
 				continue;
 
-- 
2.25.1