SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The bus clock can also be gated off in either the PARTIAL or SLUMBER state, if the software guarantees there is nothing in flight, the clock can be stopped and started without glitches, and the clock can be restarted quickly when activity is initiated from the device side.
The following steps outline the procedure to stop the clock:
If a SATA drive attached to the SATA HBA port has not entered a low power state (PARTIAL or SLUMBER), the user must not set the SATA_SYSCONFIG[16]OVERRIDE0 bit; otherwise, the link layer can be ruined, resulting in indeterminate SATA controller behavior.