ata: Rework power management behavior a bit

After continued reports of corruption using iFlash adapters, I went
digging for more clues, and this combination of changes seemed to
solve data corruption with the iFlash adapters on the ipod video:

 1) Instead of SLEEP, use STANDBY_IMMEDIATE when we detect drive
    as an SSD or CFA-compliant device.  The latter is technically higher
    power than the former, but what this means in practice is unclear.
 2) Don't check ATA powermanagement flag prior to issuing powermgmt
    commands. This reverts the previous "workaround" for the FC1307A --
    and PM is a mandatory part of the ATA spec for any CFA device.
 3) Prior to issuing SLEEP/STANDBY_IMMEDIATE, issue FLUSH CACHE.  The
    ATA spec says this is redundant for the latter, but says nothing
    about the former.  Either way it is always safe to call first.
 4) Delete all other FC1307A_WORKAROUND code related to powermgmt flags.

Change-Id: I492d06664c097d9bbd5cccfb9f5b516da165b1ee

0 files changed, 0 insertions, 0 deletions