#27 Disabling Seagate auto powersaving mode fails

[linux fan]

hdparm - get/set hard disk parameters - version v9.27
-Z Disable Seagate auto-powersaving mode
always fails with error:

hdparm -Z /dev/sda
/dev/sda:
disabling Seagate auto powersaving mode
HDIO_DRIVE_CMD(seagatepwrsave) failed: Input/output error

Disk model:
hdparm -I /dev/sda
ATA device, with non-removable media
Model Number: ST3500641AS
Serial Number: 3PM1C9S5
Firmware Revision: 3.AAE

uname -a
Linux lfs 2.6.31.4-noremap #2 Sun Oct 18 17:31:07 EDT 2009 i686 pentium3 i386 GNU/Linux

From /var/log/sys.log:
Nov 21 08:19:40 lfs kernel: sata_promise 0000:00:0d.0: PCI INT A -> Link[LNKD] -> GSI 9 (level, low) -> IRQ 9
Nov 21 08:19:40 lfs kernel: scsi0 : sata_promise
Nov 21 08:19:40 lfs kernel: scsi1 : sata_promise
Nov 21 08:19:40 lfs kernel: scsi2 : sata_promise
Nov 21 08:19:40 lfs kernel: scsi3 : sata_promise
Nov 21 08:19:40 lfs kernel: ata1: SATA max UDMA/133 mmio m4096@0xd4800000 ata 0xd4800200 irq 9
Nov 21 08:19:40 lfs kernel: ata2: SATA max UDMA/133 mmio m4096@0xd4800000 ata 0xd4800280 irq 9
Nov 21 08:19:40 lfs kernel: ata3: SATA max UDMA/133 mmio m4096@0xd4800000 ata 0xd4800300 irq 9
Nov 21 08:19:40 lfs kernel: ata4: SATA max UDMA/133 mmio m4096@0xd4800000 ata 0xd4800380 irq 9
...
Nov 21 08:19:40 lfs kernel: ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
Nov 21 08:19:40 lfs kernel: ata2.00: configured for UDMA/133
Nov 21 08:19:40 lfs kernel: ata2: EH complete
Nov 21 08:19:40 lfs kernel: scsi 1:0:0:0: Direct-Access ATA ST3500641AS 3.AA PQ: 0 ANSI: 5
Nov 21 08:19:40 lfs kernel: sd 1:0:0:0: [sda] 976773168 512-byte logical blocks