Hi all, I was hoping you might help resolve some confusion on my part regarding I2C. I have a Thinkpad T42, and as far as I can tell, it has an Intel 82801 SMBus (which I gather from the output of lspci), and a National Semiconductor PC87591 sensors chip (which I read at http://archives.andrew.net.au/lm-sensors/msg31277.html). I'm not completely new to Linux, but I don't know much about I2C, although I've read some of the basics. From what I understand, I2C can be used by lm-sensors, and possibly by ACPI. I've read ominous things about lm-sensors in regards to Thinkpads (at http://www.thinkwiki.org/wiki/Problem_with_lm-sensors), but I don't know if this means that I should abandon trying to get any benefit from the I2C bus. Here's a few questions I have: 1. Do I need to have the kernel configured for /both/ hardware bus support /and/ sensors chip support to get any value out of I2C, or is it possible there are other devices on the bus that might be of service? 2. Is there any great way to confirm that Thinkpad T42's actually have a NS PC87591 sensors chip? I was hesitant to run the sensors-detect on my Thinkpad because of sharp warnings I found on-line. 3. If I can't use lm-sensors on a Thinkpad, does ACPI rely at all on I2C? If so, what kind of configuration do I need to set that up (kernel-wise or user-space-wise)? 4. How should I test that I2C is working when everything's all set up? I appreciate any feedback you can provide, even if just pointing me towards other resources. Thanks, Sukant
