Comment 3 for bug 913050

I'm affected by this too (Same Notebook: Thinkpad T500, different HD SAMSUNG HN-M101MBB):

hdparm -B127 /dev/sda
/dev/sda:
 setting Advanced Power Management level to 0x7f (127)
 APM_level = 127

so in my case it sticks to 127, but it spins down way to often (i.e. after a couple of seconds ~30? reading a web page)

hdparm -i /dev/sda

/dev/sda:

 Model=SAMSUNG HN-M101MBB, FwRev=2AR10001, SerialNo=S2R8J9HB908804
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
 BuffType=unknown, BuffSize=8192kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=1953525168
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes: pio0 pio1 pio2 pio3 pio4
 DMA modes: mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
 AdvancedPM=yes: disabled (255) WriteCache=enabled
 Drive conforms to: unknown: ATA/ATAPI-0,1,2,3,4,5,6,7