Intel ICH7 SMBus support, ichsmb(4)

Bruce M Simpson bms at
Wed Sep 10 22:19:12 UTC 2008

Hi there,

I have been looking at a system which has the Intel ICH7 south bridge.

Whenever I try to probe the SMBus on this system with 'smbmsg -p', I get 
a lot of status=41 timeout messages in dmesg from the ichsmb(4) driver.

I have been given the addresses of the SMBus peripherals and have tried 
initiating reads to their register space directly using 'smbmsg', with 
the same result.

 * Has anyone seen the same issues with the ICH7?

 * Does anyone know of any userland code I could use as an alternative 
to the ichsmb(4) driver?

I looked at mbmon, it appears it relies on the smb(4) drivers; its 
direct ISA access only works for specific hardware monitoring chips 
which appear on the ISA/LPC bus and does not implement SMBus bit-banging 
in userland.

Many many thanks for any help you can provide.


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