Prev: WD My Book Essential drive questions
Next: ARGOSY - HD363N - Network Storage
From: Frantisek.Rysanek on 20 Oct 2006 09:48
Dear Everyone,

while investigating the theoretical background of some recent
SuperMicro SAS backplanes with the AMI MG9072 enclosure management
processor, I've ended up with the following unanswered question:
it would seem that "enclosure management over I2C", as specified in the
SATA 2.5 spec, implies the use of multi-master I2C. The host PC or the
RAID controller effectively sends a SCSI command encapsulated in I2C to
the enclosure backplane processor (I2C write transaction), then the
backplane processor and the host machine switch roles on the I2C bus,
and the backplane writes a response to the host (another I2C write
transaction).

Is this indeed the case? This switching of I2C roles? Effectively
meaning multi-master I2C operations?

I was looking forward to talking to the backplane from Linux via
lm-sensors. If this is multi-master I2C, I'm out of luck :-/

Any ideas are welcome...

Frank Rysanek

References:
http://www.knowledgetek.com/datastorage/courses/SATA__2.5_Gold.pdf
http://www.t10.org/ftp/t10/drafts/ses2/ses2r15.pdf
http://www.megatrends.com/support/doc/9070-71-72-73-datasheet.pdf
http://www.qlogic.com/documents/datasheets/products_data/gem/gem424.datasheet.pdf

 | 
Pages: 1
Prev: WD My Book Essential drive questions
Next: ARGOSY - HD363N - Network Storage