i2c-i801 partially broken on Lynx Point PCH?

[Jean Delvare <jdelvare@suse.de>]

Hi Seth,

In commit 062737fb6d90 you added support for the Intel Lynx Point PCH
to the i2c-i801 driver. I happen to have a machine with this chipset
since a few weeks, and found that the i2c-i801 driver doesn't work
properly on it. Specifically, the eeprom driver return 0xff for all
EEPROM bytes. The at24 driver fails too, with a timeout.

After some testing using i2cdetect, i2cdump and i2cget, I found that
some I2C transactions work (SMBUS_QUICK, SMBUS_READ_BYTE,
SMBUS_READ_BYTE_DATA, SMBUS_READ_WORD_DATA, SMBUS_READ_BLOCK_DATA),
however others do not (SMBUS_WRITE_BYTE, SMBUS_READ_I2C_BLOCK.) I can't
easily test other transaction types as all I have on the SMBus are SPD
EEPROMs on my memory modules.

Did you test the i2c-i801 driver on an actual Lynx Point PCH chipset?
Or did you only add the PCI ID of the device, assuming it would work?

-- 
Jean Delvare
SUSE L3 Support