On Wed, 11 May 2016 09:34:52 +0200, Jean Delvare wrote: > 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? As an additional data point, I managed to find a machine on the SUSE network with a Lynx Point PCH. I tested it and everything works fine there. So not all systems with the Lynx Point PCH [8086:8c22] have the problem. One difference between my system and the working one is the PCI device revision (04 for me, 05 for the working machine.) So maybe it has something to do with the revision. Or maybe it's a problem with the way the BIOS initializes the device (my system is from Dell, the working one from Intel.) -- Jean Delvare SUSE L3 Support -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
