ide: ide_id_has_flush_cache_ext() -> ata_id_flush_ext_enabled()

* Add ata_id_flush_ext_enabled() inline helper to <linux/ata.h>.

* ide_id_has_flush_cache_ext() -> ata_id_flush_ext_enabled()

  The latter one also checks if the command is marked as
  supported in word 83 and validity of words 83 & 86.

Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/ata.h b/include/linux/ata.h
index 921cf0fc337f..81d9adeb819e 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -574,6 +574,19 @@ static inline int ata_id_has_flush_ext(const u16 *id)
         return id[ATA_ID_COMMAND_SET_2] & (1 << 13);
 }
 
+static inline int ata_id_flush_ext_enabled(const u16 *id)
+{
+        if (ata_id_has_flush_ext(id) == 0)
+                return 0;
+        if ((id[ATA_ID_CSF_DEFAULT] & 0xC000) != 0x4000)
+                return 0;
+        /*
+         * some Maxtor disks have bit 13 defined incorrectly
+         * so check bit 10 too
+         */
+        return (id[ATA_ID_CFS_ENABLE_2] & 0x2400) == 0x2400;
+}
+
 static inline int ata_id_has_lba48(const u16 *id)
 {
         if ((id[ATA_ID_COMMAND_SET_2] & 0xC000) != 0x4000)