* LAN9514 eeprom problems
@ 2011-09-16 5:20 John Crosbie
0 siblings, 0 replies; only message in thread
From: John Crosbie @ 2011-09-16 5:20 UTC (permalink / raw)
To: steve.glendinning, netdev
Steve,
I am working on an ARM7 board that contains a LAN9514 with 93LC66A
eeprom. The Linux kernel version is 2.6.32. I am seeing problems
programming the eeprom with ethtool.
If I read then it works as expected:
ethtool -e usb0
will give 512 ff's
Then I issue the command:
ethtool -E usb0 magic 0x9500 offset 0 length 1 value 0xdd
and get:
[ 72.779431] usb0: eeprom: EWEN a0000000
[ 72.784211] usb0: eeprom ready
[ 72.818265] usb0: EEPROM read operation timeout val=30000400
Cannot set EEPROM data: Input/output error
The 1st two kernel messages have been added by me along with printing the value.
I can see with a o'scope that the signalling at the chip looks good
but it appears that the 9514 returns timeout before the 93LC66 has
finished its writing busy cycle.
After doing this, if I read again then I get a timeout again:
root@2065:~# ethtool -e usb0
[ 95.889447] usb0: EEPROM read operation timeout val=00000400
Cannot get EEPROM data: Input/output error
I have to reboot to get read to work again.
My problem is that I cannot find any register level specs for the
9514. I have the data sheet and the software manual. The datasheet
describes the hardware pins and the software manual describes the
device drivers but there is a big document missing inbetween these
two.
I have seen that the driver provided on the SMSC website performs many
retries that the kernel.org driver does not when reading and writing
registers. Are these really required. Any suggestions/pointer would
be appreciated.
Regards,
John Crosbie
Excelfore
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