Hello,

I am currently working on power management of CD / DVD / BD devices and observe a behavior that does not seem spec-compliant. I’d like to confirm with the Fuji / MMC committee that such behavior is out of spec.

SPC-3r23 says:

“If the logical unit is in a power condition other than the active power condition when a REQUEST SENSE command

is received and there is no ACA condition, it shall return the sense key set to NO SENSE and the additional sense

code set to one of the following:

a) LOW POWER CONDITION ON if the reason for entry into the power condition is unknown;

b) IDLE CONDITION ACTIVATED BY TIMER if the logical unit entered the idle power condition due to the idle

condition timer (see 7.4.12);

c) STANDBY CONDITION ACTIVATED BY TIMER if the logical unit entered the standby power condition due

to the standby condition timer (see 7.4.12);

d) IDLE CONDITION ACTIVATED BY COMMAND if the logical unit entered the idle power condition due to

receipt of a command requiring the idle power condition while it was in the standby power condition; or

e) Another additional sense code based on requirements specified in a command standard (see 3.1.18).

On completion of the command the logical unit shall return to the same power condition that was active before the

REQUEST SENSE command was received. A REQUEST SENSE command shall not reset any power condition

timers.”

I am issuing the following to get the device to Idle State:

Then query the state with Request Sense, but I don’t see the power condition in the additional sense code:

Shouldn’t a spec-compliant device return its current power state in the request sense answer? Do CD / DVD / BD drives use a different command to indicate their current power state?

With regards,

David.