OSDev.org

According to AHCI spec:

...to enter these device states(D1,D2,or D3), software may issue a command to the device to enter the low power state(IDLE IMMEDIATE for D1, STANDBY(IMMEDIATE) for D2, SLEEP for D3). Then put the interface into a Slumber state...

Now I can issue these commands to device and put the interface into slumber mode successfully in DOS mode. Then I found I can "wakeup" SATA drive from D1 and D2 by just issuing Identify Device Command(0xEC) to it.

BUT for device in D3 state, issuing 0xEC causes system hang... Could anyone know the reason why

I found issuing COMRESET to device can "wake-up" device in D3...