From: Colin Ian King <colin.king@canonical.com>
To: Vladimir Oltean <vladimir.oltean@nxp.com>,
Andrew Lunn <andrew@lunn.ch>,
Florian Fainelli <f.fainelli@gmail.com>,
Heiner Kallweit <hkallweit1@gmail.com>,
Russell King <linux@armlinux.org.uk>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
netdev@vger.kernel.org
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: re: net: phy: continue searching for C45 MMDs even if first returned ffff:ffff
Date: Mon, 20 Jul 2020 17:21:13 +0100 [thread overview]
Message-ID: <4131864f-9e3e-9814-5f4d-16c93648bce2@canonical.com> (raw)
Hi,
Static analysis by Coverity has found a potential issue with the
following commit in /drivers/net/phy/phy_device.c:
commit bba238ed037c60242332dd1e4c5778af9eba4d9b
Author: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Sun Jul 12 19:48:15 2020 +0300
net: phy: continue searching for C45 MMDs even if first returned
ffff:ffff
The analysis is as follows:
735 * for 802.3 c45 complied PHYs, so don't probe it at first.
736 */
dead_error_condition: The condition (devs_in_pkg & 0x1fffffffU) ==
0x1fffffffU cannot be true.
737 for (i = 1; i < MDIO_MMD_NUM && devs_in_pkg == 0 &&
const: At condition (devs_in_pkg & 0x1fffffffU) == 0x1fffffffU, the
value of devs_in_pkg must be equal to 0.
738 (devs_in_pkg & 0x1fffffff) == 0x1fffffff; i++) {
Logically dead code (DEADCODE)dead_error_line: Execution cannot reach
this statement: if (i == 30 || i == 31) {
To summarize, if devs_in_pkg is zero, then (devs_in_pkg & 0x1fffffffU)
== 0x1fffffffU can never be true, so the loop is never iterated over.
Colin
next reply other threads:[~2020-07-20 16:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-20 16:21 Colin Ian King [this message]
2020-07-20 16:31 ` net: phy: continue searching for C45 MMDs even if first returned ffff:ffff Vladimir Oltean
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