Revert "libata: check SATA_SETTINGS log with HW Feature Ctrl"

This reverts commit de90cd7.

Shane Huang writes:

  Please suspend this patch because I just received two new
  DevSlp drives but found word 78 bit 5 is _not_ set.

  I'm checking with the drive vendor whether he gave me
  the wrong information. If bit 5 is not the necessary and
  sufficient condition, I will implement another patch to
  replace ata_device->sata_settings into ->devslp_timing.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-core.c

@@ -2331,8 +2331,9 @@ int ata_dev_configure(struct ata_device *dev)
 
 		/* Obtain SATA Settings page from Identify Device Data Log,
 		 * which contains DevSlp timing variables etc.
+		 * Exclude old devices with ata_id_has_ncq()
 		 */
-		if (ata_id_has_hw_feature_ctrl(dev->id)) {
+		if (ata_id_has_ncq(dev->id)) {
 			err_mask = ata_read_log_page(dev,
 						     ATA_LOG_SATA_ID_DEV_DATA,
 						     ATA_LOG_SATA_SETTINGS,

include/linux/ata.h

@@ -593,7 +593,6 @@ static inline int ata_is_data(u8 prot)
 #define ata_id_cdb_intr(id)	(((id)[ATA_ID_CONFIG] & 0x60) == 0x20)
 #define ata_id_has_da(id)	((id)[ATA_ID_SATA_CAPABILITY_2] & (1 << 4))
 #define ata_id_has_devslp(id)	((id)[ATA_ID_FEATURE_SUPP] & (1 << 8))
-#define ata_id_has_hw_feature_ctrl(id)	((id)[ATA_ID_FEATURE_SUPP] & (1 << 5))
 
 static inline bool ata_id_has_hipm(const u16 *id)
 {