From: Andrew Lunn <andrew@lunn.ch>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Heiner Kallweit <hkallweit1@gmail.com>,
Woojung Huh <woojung.huh@microchip.com>,
Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Daniel Wagner <dwagner@suse.de>,
netdev@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com,
Stefan Wahren <wahrenst@gmx.net>,
linux-arm-kernel@lists.infradead.org,
linux-rpi-kernel@lists.infradead.org
Subject: Re: lan78xx and phy_state_machine
Date: Wed, 16 Oct 2019 17:36:46 +0200 [thread overview]
Message-ID: <20191016153646.GG17013@lunn.ch> (raw)
In-Reply-To: <20191015220925.GW25745@shell.armlinux.org.uk>
> > - lan78xx_phy_init() (incl. the call to phy_connect_direct()) is called
> > after register_netdev(). This may cause races.
>
> That isn't a problem. We have lots of network device drivers that do
> this - in their open() function.
Hi Russell
Actually, here is it. lan7801_phy_init() finds the PHY device and
connects it to the MAC. lan78xx_open() calls phy_start(), with the
assumption lan7801_phy_init() has been called.
But the stack trace just provided shows this assumption is wrong. As
soon a register_netdev() is called, the kernel auto configuration is
kicking in and opening the device.
lan78xx_phy_init() needs to happen before register_netdev(), or inside
lan78xx_open().
Andrew
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Lunn <andrew@lunn.ch>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Woojung Huh <woojung.huh@microchip.com>,
linux-rpi-kernel@lists.infradead.org,
Florian Fainelli <f.fainelli@gmail.com>,
Daniel Wagner <dwagner@suse.de>,
netdev@vger.kernel.org,
Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
bcm-kernel-feedback-list@broadcom.com,
Stefan Wahren <wahrenst@gmx.net>,
linux-arm-kernel@lists.infradead.org,
Heiner Kallweit <hkallweit1@gmail.com>
Subject: Re: lan78xx and phy_state_machine
Date: Wed, 16 Oct 2019 17:36:46 +0200 [thread overview]
Message-ID: <20191016153646.GG17013@lunn.ch> (raw)
In-Reply-To: <20191015220925.GW25745@shell.armlinux.org.uk>
> > - lan78xx_phy_init() (incl. the call to phy_connect_direct()) is called
> > after register_netdev(). This may cause races.
>
> That isn't a problem. We have lots of network device drivers that do
> this - in their open() function.
Hi Russell
Actually, here is it. lan7801_phy_init() finds the PHY device and
connects it to the MAC. lan78xx_open() calls phy_start(), with the
assumption lan7801_phy_init() has been called.
But the stack trace just provided shows this assumption is wrong. As
soon a register_netdev() is called, the kernel auto configuration is
kicking in and opening the device.
lan78xx_phy_init() needs to happen before register_netdev(), or inside
lan78xx_open().
Andrew
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linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-10-16 15:36 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-14 14:06 lan78xx and phy_state_machine Daniel Wagner
2019-10-14 14:32 ` Daniel Wagner
2019-10-14 18:15 ` Stefan Wahren
2019-10-14 19:28 ` Daniel Wagner
2019-10-14 16:30 ` Russell King - ARM Linux admin
2019-10-14 19:25 ` Daniel Wagner
2019-10-14 19:51 ` Stefan Wahren
2019-10-14 19:51 ` Stefan Wahren
2019-10-14 20:20 ` Heiner Kallweit
2019-10-14 20:20 ` Heiner Kallweit
2019-10-14 22:12 ` Russell King - ARM Linux admin
2019-10-14 22:12 ` Russell King - ARM Linux admin
2019-10-15 19:38 ` Heiner Kallweit
2019-10-15 19:38 ` Heiner Kallweit
2019-10-15 22:09 ` Russell King - ARM Linux admin
2019-10-15 22:09 ` Russell King - ARM Linux admin
2019-10-16 15:36 ` Andrew Lunn [this message]
2019-10-16 15:36 ` Andrew Lunn
2019-10-16 5:48 ` Stefan Wahren
2019-10-16 5:48 ` Stefan Wahren
2019-10-15 0:14 ` Andrew Lunn
2019-10-14 23:53 ` Andrew Lunn
2019-10-15 0:53 ` Andrew Lunn
2019-10-15 17:16 ` Daniel Wagner
2019-10-15 17:16 ` Daniel Wagner
2019-10-16 14:25 ` Daniel Wagner
2019-10-16 14:25 ` Daniel Wagner
2019-10-16 15:51 ` Andrew Lunn
2019-10-16 15:51 ` Andrew Lunn
2019-10-17 6:52 ` Daniel Wagner
2019-10-17 6:52 ` Daniel Wagner
2019-10-17 13:15 ` Andrew Lunn
2019-10-17 13:15 ` Andrew Lunn
2019-10-17 17:05 ` Stefan Wahren
2019-10-17 17:05 ` Stefan Wahren
2019-10-17 17:41 ` Daniel Wagner
2019-10-17 17:41 ` Daniel Wagner
2019-10-17 17:52 ` Stefan Wahren
2019-10-17 17:52 ` Stefan Wahren
2019-10-17 18:14 ` Daniel Wagner
2019-10-17 18:14 ` Daniel Wagner
2019-10-17 18:25 ` Andrew Lunn
2019-10-17 18:25 ` Andrew Lunn
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