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Dead eth0 PHY after ifconfig eth0 up with no ethernet cable
Board: am1808 EVM
Kernel: prebuilt uImage-am180x-evm.bin (SDK: ti-sdk-am180x-evm-05.03.02.00-Linux-x86-Install)
Rootfs: extracted base-rootfs-am180x-evm.tar.gz (Seems not relevant. It's from the SDK, too.)
I use AM1808 EVM and encounter a problem that the ethernet PHY is easily dead (about 50%) if I "ifconfig eth0 up" without plugging in ethernet cable.
1. Power on WITHOUT plugging ethernet cable (MUST)
2. Boot into linux shell
> ifconfig eth0 updavinci_mdio davinci_mdio.0: resetting idled controllernet eth0: attached PHY driver [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=0:00, id=7c0f1)
(I traced and found the behavior is: "up" -> reset emac -> reset mdio)
3. Plug in ethernet cable after 5 sec--> Problem: Ethernet port LED isn't blinking anymore! Of course, PHY can't link up. Looks like the PHY is dead! Replugging or "ifconfig down and up" can't help PHY recover.
What I can do is reboot the system and let PHY recover.
Q1: Is the PHY module inside am1808? Or it resides on the board? Should it be reset after MDIO reset?
Q2: Is the PHY dead?
I suppose this usage is very common. Please help us clarify and solve the problem.
I had some other strange problems with the davinci emac in the past, so I would like to reproduce your problem here. Could you please post the output of ifconfig after the PHY is dead? Please also post the kernel version of the SDK (output of uname -a)
At that point, no message is output.
1. Boot into linux shell without plugging ethernet cable
~ # ifconfig eth0 up[ 66.364031] davinci_mdio davinci_mdio.0: resetting idled controller[ 66.371239] net eth0: attached PHY driver [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=0:00, id=7c0f1)
2. Plug in ethernet cable...No blinking PHY LED...
/ # ifconfig eth0 up/ # ifconfig eth0 up/ # ifconfig eth0 down/ # ifconfig eth0 updavinci_mdio davinci_mdio.0: resetting idled controllernet eth0: attached PHY driver [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=0:00, id=7c0f1)/ # ifconfig eth0 up
3. Still no blinking PHY LED...
/ # uname -aLinux (none) 2.6.37 #2 PREEMPT Thu Dec 15 12:43:56 CST 2011 armv5tejl GNU/Linux/ #
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