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From: Jean Delvare <jdelvare@suse.de>
To: Seth Heasley <seth.heasley@intel.com>
Cc: Linux I2C <linux-i2c@vger.kernel.org>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Jarkko Nikula <jarkko.nikula@linux.intel.com>
Subject: i2c-i801 partially broken on Lynx Point PCH?
Date: Wed, 11 May 2016 09:34:52 +0200	[thread overview]
Message-ID: <20160511093452.5bc2614c@endymion> (raw)

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

             reply	other threads:[~2016-05-11  7:34 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-11  7:34 Jean Delvare [this message]
2016-05-11  8:43 ` i2c-i801 partially broken on Lynx Point PCH? Jean Delvare
2016-05-11 16:15   ` Heasley, Seth
2016-05-11 17:34     ` Jean Delvare
2016-05-11 17:46       ` Heasley, Seth
2016-05-18 12:05   ` Jean Delvare
2016-05-18 13:02     ` Wolfram Sang
2016-05-18 13:20     ` Jean Delvare
2016-05-19 11:02       ` Jarkko Nikula
2016-05-19 11:29         ` Jean Delvare

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