Comment 48 for bug 539467

Running Linux buzz 2.6.37-11-generic #25-Ubuntu SMP Tue Dec 21 23:42:56 UTC 2010 x86_64 GNU/Linux (latest natty kernel at the time of writing)
pm-utils:
  Installed: 1.4.1-4

After unplugging the AC the pm-suspend log gets
"""
/usr/lib/pm-utils/power.d/readahead true: success.
Running hook /usr/lib/pm-utils/power.d/sata_alpm true:
Setting SATA APLM on host2 to min_power...Done.
Setting SATA APLM on host3 to min_power...Done.
Setting SATA APLM on host4 to min_power...Done.
Setting SATA APLM on host5 to min_power...Done.
"""
And subsequent usage of the system is rather hard. HDD led stays on for prolonged periods of time, dmesg hangs for some seconds (i believe binary is being read from disk), then the following can be found in the output:
"""
[13870.046027] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x150000 action 0x6 frozen
[13870.046044] ata3: SError: { PHYRdyChg CommWake Dispar }
[13870.046052] ata3.00: failed command: SET FEATURES
[13870.046070] ata3.00: cmd ef/05:fe:00:00:00/00:00:00:00:00/40 tag 0
[13870.046073] res 40/00:ff:00:00:00/00:00:00:00:00/40 Emask 0x4 (timeout)
[13870.046081] ata3.00: status: { DRDY }
[13870.046094] ata3: hard resetting link
[13870.390116] ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[13870.693978] ata3.00: configured for UDMA/133
[13870.694151] ata3: EH complete
"""

I have disabled the aplm control by by placing
"""
#!/bin/sh
export SATA_ALPM_ENABLE=false
"""
to /etc/pm/config.d/00-no-sata-alpm but that is just a workaround which the users will not be really happy with if it does not work out-of-the-box.