Seagate Fibre Channel Interface - Manual (Page 183)

Fibre Channel Interface Manual, Rev. D 169
Additional Inquiry command information
The Inquiry command returns Check Condition status only when the disc drive cannot return the requested
Inquiry data.
If an Inquiry command is received from an initiator with a pending unit attention condition (i.e., before the disc
drive reports Check Condition status), the disc drive performs the Inquiry command and does not clear the Unit
Attention condition.
The Inquiry command is typically used by the initiator after a reset or power-up condition to determine the
device types for system configuration. To minimize delays after a reset or power-up condition, the standard
Inquiry data is available without incurring any media access delays. Since the disc drive stores some of the
Inquiry data on the device media it may return zeros or ASCII spaces (20h) in those fields until the data is avail-
able.
The Inquiry data may change as the disc drive executes its initialization sequence or in response to a Change
Definition command. For example, the disc drive may contain a minimum command set in its nonvolatile mem-
ory and load its final firmware from the medium when it becomes ready. After it has loaded the firmware it may
support more options and therefore return different supported options information in the Inquiry data.