SAS SMP support for non-expanders
Elliott, Robert (Server Storage)
Elliott at hp.com
Fri Feb 7 13:12:10 PST 2003
* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert (Server Storage)" <Elliott at hp.com>
The current rules for supporting SMP functions are as follows:
REPORT GENERAL: This function may implemented by any type of device and
should be implemented by expander devices.
REPORT MANUFACTURER INFORMATION: This function may be implemented by
any type of device.
DISCOVER: This function shall be implemented by all expander devices and
shall not be implemented by other types of devices.
REPORT PHY ERROR LOG: This function may implemented by any type of
REPORT PHY SATA: This function shall be implemented by expander devices
supporting attachment to SATA devices. This function shall not be
implemented by any other type of device.
REPORT ROUTE INFORMATION: Expander devices shall support this function
the expander route indexes field is non-zero in the REPORT GENERAL
CONFIGURE ROUTE INFORMATION: Expander devices shall support this
if the configurable route table field is set to one in the REPORT
PHY CONTROL: This function may implemented by any type of device.
1) The REPORT GENERAL function should be mandatory for any device
implementing an SMP target port. This returns the Number of Phys field
which should constrain the Phy Identifier field used by most of the
other functions. The Expander Change Count and Expander Route Indexes
fields only apply to expanders.
2) The DISCOVER function is marked as "expander only" but should
be allowed for end devices (particularly for end devices with
These fields are applicable to end devices:
Attached Device Type
Attached SAS address
Negotiated Physical Link Rate
Attached SSP/STP/SMP Initiator Target bits
Programmed/Hardware Minimum/Maximum Physical Link Rates
These fields are only meaningful in expanders:
Partial Pathway Timeout Value
3) REPORT PHY SATA needs to be allowed in end devices if we want native
STP target ports to be able to implement affiliations.
STP/SMP target port at SAS address A
one phy (phy 0)
SMP connection to A can access:
Number of Phys = 1
REPORT PHY SATA for Phy 0
STP SAS Address = A
Register Device to Host FIS = power-on register contents
(native STP target has nowhere to deliver this at power-on;
storing here makes it work like a SATA target behind an STP/SATA
Affiliation Valid, Affiliated STP Initiator SAS Address = used
to report affiliation status like an STP/SATA bridge would do
PHY CONTROL for Phy 0
Clear Affiliation = supported like an STP/SATA bridge
Rob Elliott, elliott at hp.com
Hewlett-Packard Industry Standard Server Storage Advanced Technology
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