Exact same problem here with freshly installed Ubuntu Studio 12.10. Installed all 169 updates + new kernel right after install from dvd => version is now : Linux version 3.5.0-21-lowlatency (buildd@allspice) (gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1) ) #19-Ubuntu SMP PREEMPT Tue Dec 18 18:37:29 UTC 2012 (Ubuntu 3.5.0-21.19-lowlatency 3.5.7.1) I previously had Ubuntu Studio 10.10 installed on same hardware and it did not have problem to suspend, problems came with 12.10 : I can neither suspend (suspend process gives up and machine comes back on after 30s timeout), nor shutdown properly (have to force stop with power button). Common hw/drivers with original syslog posted by ill : - sata_nv and snd_hda_intel (NVidia chipset) => mine is MCP55 Pro (Tyan S2915 mobo) - NVidia graphics card (I'm using nvidia's driver instead of nouveau) => mine is 9600GT My machine hosts 4 hard drives among which 2 seem to stop and the other 2 refuse to stop. My syslog (at end of post below) displays the same "invalid CHS sector 0" for 3 of the 4 drives, including the system drive. Maybe the "FLUSH CACHE EXT" error on the system disk, preceding the "invalid CHS sector 0" error, is due to the fact that the system disk is an HP-labeled server disk and not a regular one. But, the fact is that the 2 disks (scsi4 and scsi10) that fail to stop exhibit the same "START_STOP FAILED" error, and after a bit of searching through the logs, it appears that they are the only 2 disks that are not partitioned. I formatted them from Ubuntu Studio 10.10 as whole ext4 volumes and they seem to hold no partition table at all, as they both cause an "unknown partition table" warning during boot. Once boot is finished, they are nevertheless mountable and writable, as removable disks (they do not hold any system data). One more info : before formatting under Ubuntu 10.10, both of these drives were exhaustively analyzed with "badblocks" tool in write mode (yes, I tend to be a little paranoid about bad sectors by now) and neither SMART, nor "badblocks" detected any problem. My best guess for filing this bug would be sata_nv or pm-utils packages. Extract from syslog : Jan 6 20:36:08 mrblack kernel: [ 1020.308371] PM: Syncing filesystems ... done. Jan 6 20:36:08 mrblack kernel: [ 1020.317152] PM: Preparing system for mem sleep Jan 6 20:36:08 mrblack kernel: [ 1020.317169] Freezing user space processes ... (elapsed 0.01 seconds) done. Jan 6 20:36:08 mrblack kernel: [ 1020.329154] Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done. Jan 6 20:36:08 mrblack kernel: [ 1020.340148] PM: Entering mem sleep Jan 6 20:36:08 mrblack kernel: [ 1020.340172] Suspending console(s) (use no_console_suspend to debug) Jan 6 20:36:08 mrblack kernel: [ 1020.340771] sd 10:0:0:0: [sdh] Synchronizing SCSI cache Jan 6 20:36:08 mrblack kernel: [ 1020.340954] sd 10:0:0:0: [sdh] Stopping disk Jan 6 20:36:08 mrblack kernel: [ 1020.341476] sd 5:0:0:0: [sdc] Synchronizing SCSI cache Jan 6 20:36:08 mrblack kernel: [ 1020.341605] sd 5:0:0:0: [sdc] Stopping disk Jan 6 20:36:08 mrblack kernel: [ 1020.341627] sd 4:0:0:0: [sdb] Synchronizing SCSI cache Jan 6 20:36:08 mrblack kernel: [ 1020.341786] sd 4:0:0:0: [sdb] Stopping disk Jan 6 20:36:08 mrblack kernel: [ 1020.341798] sd 2:0:0:0: [sda] Synchronizing SCSI cache Jan 6 20:36:08 mrblack kernel: [ 1020.344804] serial 00:0d: disabled Jan 6 20:36:08 mrblack kernel: [ 1020.344849] serial 00:0c: disabled Jan 6 20:36:08 mrblack kernel: [ 1020.344872] i8042 aux 00:06: wake-up capability disabled by ACPI Jan 6 20:36:08 mrblack kernel: [ 1020.344880] i8042 kbd 00:05: wake-up capability enabled by ACPI Jan 6 20:36:08 mrblack kernel: [ 1020.345268] ACPI handle has no context! Jan 6 20:36:08 mrblack kernel: [ 1020.683850] PM: suspend of drv:sd dev:5:0:0:0 complete after 342.373 msecs Jan 6 20:36:08 mrblack kernel: [ 1020.683871] PM: suspend of drv:scsi dev:target5:0:0 complete after 342.353 msecs Jan 6 20:36:08 mrblack kernel: [ 1020.683887] PM: suspend of drv:scsi dev:host5 complete after 341.535 msecs Jan 6 20:36:08 mrblack kernel: [ 1020.683938] PM: suspend of drv: dev:ata6 complete after 341.516 msecs Jan 6 20:36:08 mrblack kernel: [ 1020.695039] PM: suspend of drv:snd_hda_intel dev:0000:00:06.1 complete after 348.924 msecs Jan 6 20:36:08 mrblack kernel: [ 1050.720040] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen Jan 6 20:36:08 mrblack kernel: [ 1050.720044] ata5.00: failed command: STANDBY IMMEDIATE Jan 6 20:36:08 mrblack kernel: [ 1050.720050] ata5.00: cmd e0/00:00:00:00:00/00:00:00:00:00/a0 tag 0 Jan 6 20:36:08 mrblack kernel: [ 1050.720050] res 40/00:01:00:00:00/00:00:00:00:00/40 Emask 0x4 (timeout) Jan 6 20:36:08 mrblack kernel: [ 1050.720052] ata5.00: status: { DRDY } Jan 6 20:36:08 mrblack kernel: [ 1050.720057] ata5: hard resetting link Jan 6 20:36:08 mrblack kernel: [ 1050.720059] ata5: nv: skipping hardreset on occupied port Jan 6 20:36:08 mrblack kernel: [ 1050.720439] ata11.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen Jan 6 20:36:08 mrblack kernel: [ 1050.720440] ata11.00: failed command: STANDBY IMMEDIATE Jan 6 20:36:08 mrblack kernel: [ 1050.720445] ata11.00: cmd e0/00:00:00:00:00/00:00:00:00:00/a0 tag 0 Jan 6 20:36:08 mrblack kernel: [ 1050.720445] res 40/00:01:00:00:00/00:00:00:00:00/40 Emask 0x4 (timeout) Jan 6 20:36:08 mrblack kernel: [ 1050.720447] ata11.00: status: { DRDY } Jan 6 20:36:08 mrblack kernel: [ 1050.720450] ata11: hard resetting link Jan 6 20:36:08 mrblack kernel: [ 1050.720451] ata11: nv: skipping hardreset on occupied port Jan 6 20:36:08 mrblack kernel: [ 1051.174045] ata11: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Jan 6 20:36:08 mrblack kernel: [ 1051.174049] ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Jan 6 20:36:08 mrblack kernel: [ 1051.183351] ata5.00: configured for UDMA/133 Jan 6 20:36:08 mrblack kernel: [ 1051.183355] ata5.00: device reported invalid CHS sector 0 Jan 6 20:36:08 mrblack kernel: [ 1051.183358] ata11.00: configured for UDMA/133 Jan 6 20:36:08 mrblack kernel: [ 1051.183363] ata11.00: device reported invalid CHS sector 0 Jan 6 20:36:08 mrblack kernel: [ 1051.183371] ata5: EH complete Jan 6 20:36:08 mrblack kernel: [ 1051.183375] ata11: EH complete Jan 6 20:36:08 mrblack kernel: [ 1051.183391] sd 10:0:0:0: [sdh] START_STOP FAILED Jan 6 20:36:08 mrblack kernel: [ 1051.183393] sd 10:0:0:0: [sdh] Jan 6 20:36:08 mrblack kernel: [ 1051.183394] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE Jan 6 20:36:08 mrblack kernel: [ 1051.183396] sd 10:0:0:0: [sdh] Jan 6 20:36:08 mrblack kernel: [ 1051.183398] sd 4:0:0:0: [sdb] START_STOP FAILED Jan 6 20:36:08 mrblack kernel: [ 1051.183400] sd 4:0:0:0: [sdb] Jan 6 20:36:08 mrblack kernel: [ 1051.183397] Sense Key : Aborted Command [current] [descriptor] Jan 6 20:36:08 mrblack kernel: [ 1051.183403] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE Jan 6 20:36:08 mrblack kernel: [ 1051.183406] sd 10:0:0:0: [sdh] Jan 6 20:36:08 mrblack kernel: [ 1051.183406] sd 4:0:0:0: [sdb] Jan 6 20:36:08 mrblack kernel: [ 1051.183408] Add. Sense: No additional sense informationSense Key : Aborted Command Jan 6 20:36:08 mrblack kernel: [ 1051.183410] [current] [descriptor] Jan 6 20:36:08 mrblack kernel: [ 1051.183413] sd 4:0:0:0: [sdb] Jan 6 20:36:08 mrblack kernel: [ 1051.183420] dpm_run_callback(): scsi_bus_suspend+0x0/0x20 returns 134217730 Jan 6 20:36:08 mrblack kernel: [ 1051.183420] Add. Sense: No additional sense information Jan 6 20:36:08 mrblack kernel: [ 1051.183424] PM: suspend of drv:sd dev:10:0:0:0 complete after 30842.666 msecs Jan 6 20:36:08 mrblack kernel: [ 1051.183430] dpm_run_callback(): scsi_bus_suspend+0x0/0x20 returns 134217730 Jan 6 20:36:08 mrblack kernel: [ 1051.183433] PM: Device 10:0:0:0 failed to suspend async: error 134217730 Jan 6 20:36:08 mrblack kernel: [ 1051.183434] PM: suspend of drv:sd dev:4:0:0:0 complete after 30841.816 msecs Jan 6 20:36:08 mrblack kernel: [ 1051.183439] PM: Device 4:0:0:0 failed to suspend async: error 134217730 Jan 6 20:36:08 mrblack kernel: [ 1080.800411] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen Jan 6 20:36:08 mrblack kernel: [ 1080.800414] ata3.00: failed command: FLUSH CACHE EXT Jan 6 20:36:08 mrblack kernel: [ 1080.800420] ata3.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0 Jan 6 20:36:08 mrblack kernel: [ 1080.800420] res 40/00:01:00:00:00/00:00:00:00:00/40 Emask 0x4 (timeout) Jan 6 20:36:08 mrblack kernel: [ 1080.800422] ata3.00: status: { DRDY } Jan 6 20:36:08 mrblack kernel: [ 1080.800426] ata3: hard resetting link Jan 6 20:36:08 mrblack kernel: [ 1080.800428] ata3: nv: skipping hardreset on occupied port Jan 6 20:36:08 mrblack kernel: [ 1081.254056] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Jan 6 20:36:08 mrblack kernel: [ 1081.263138] ata3.00: configured for UDMA/100 Jan 6 20:36:08 mrblack kernel: [ 1081.263140] ata3.00: retrying FLUSH 0xea Emask 0x4 Jan 6 20:36:08 mrblack kernel: [ 1081.263349] ata3.00: device reported invalid CHS sector 0 Jan 6 20:36:08 mrblack kernel: [ 1081.263360] ata3: EH complete Jan 6 20:36:08 mrblack kernel: [ 1081.263575] sd 2:0:0:0: [sda] Stopping disk Jan 6 20:36:08 mrblack kernel: [ 1081.544294] PM: suspend of drv:sd dev:2:0:0:0 complete after 61202.502 msecs Jan 6 20:36:08 mrblack kernel: [ 1081.544364] PM: Some devices failed to suspend Hope it helps. Eric