starting ethernet switch in SMI mode

Vanalme Filip F.Vanalme at
Wed Jul 4 07:53:39 EDT 2012


On our board with i.MX27 processor, we have a Micrel 5-port Managed Ethernet switch (ksz8895mq). When starting in normal MII mode, from the Barebox prompt, I can get an IP address by executing the dhcp command.
When I change the switch's mode to SPI (via hardware strapping), I'm not able to get an IP address anymore via DHCP. In this mode, one has to write to a register in the switch to make the switch start. So, within our startup code, I added some code to start the switch. Reading back the register, I see that the bit is set, so I assume the switch sould be running at that moment. However, when executing the dhcp command, I get "phy0: Autonegotiation timeout".
That's strange, because, when I boot to Linux kernel, the kernel starts up without any problem and gets an IP address via DHCP. So in Linux, it's doing OK.
Because it is working in Linux, I'm quite sure the switch was started in a correct way.
I don't understand why Barebox is unable to contact the switch while there's no problem in Linux to do the same. Anyone any idea on this problem ?

Thanks in advance !


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Filip Vanalme

Senior Development Engineer

Tel. +32 51 30.30.45

Fax +32 51 33.18.86

Televic NV * Leo Bekaertlaan 1 * 8870 Izegem * Belgium
Company number 0402.757.955 * RPR Kortrijk

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