ata: Rework how flushing, sleeping, and power off interacts

 * FLUSH_EXT is used if featureflag is set and we are using LBA48
   (unconditionally used for CE-ATA on ipod6g)
 * FLUSH is used if featureflag is set (ATA6+) or if device claims to be ATA5+

 * Rename ata_disk_can_power_off() to ata_disk_can_sleep() as that is
   what it actually tests for.  Only use it to gate issuing the
   STANDBY IMMEDIATE command.
 * Restore behavior of ata_disk_is_active() to return 1 if drive is
   "spinning" or powered up.
 * Allow poweroff if drive claims PM support OR we are able to issue
   FLUSH/FLUSH_EXT commands.

 * Added ata_flush() to explicitly trigger a flush operation, and hook it
   up to storage_flush() in the device shutdown path. (Flushes were
   only previously used in the storage device power management path)

 * After issuing all settings, re-issue IDENTIFY_DEVICE to make sure
   it reflects everything we've enabled.

 * Update manual section on Flash/SSD mods.

Change-Id: I6770a54ef3a87f4c47120bcb96c944a6652f1bf4

1 files changed, 4 insertions, 2 deletions

diff --git a/firmware/export/ata.h b/firmware/export/ata.h
index 0d84a91524..dfa73eebf5 100644
--- a/firmware/export/ata.h
+++ b/firmware/export/ata.h
@@ -208,8 +208,8 @@ static inline int ata_disk_isssd(void)
            );
 }
 
-/* Returns 1 if the drive can be powered off safely */
-static inline int ata_disk_can_poweroff(void)
+/* Returns 1 if the drive supports power management commands */
+static inline int ata_disk_can_sleep(void)
 {
     unsigned short *identify_info = ata_get_identify();
     /* Only devices that claim to support PM can be safely powered off.
@@ -217,6 +217,8 @@ static inline int ata_disk_can_poweroff(void)
     return (identify_info[82] & (1<<3) && identify_info[85] & (1<<3));
 }
 
+int ata_flush(void);
+
 #ifdef HAVE_ATA_DMA
 /* Returns current DMA mode */
 int ata_get_dma_mode(void);