And yes- it's in libata!!
SSD is eating brains only when libata.dma>=4

http://www.kernel.org/doc/Documentation/kernel-parameters.txt

> libata.dma=	[LIBATA] DMA control
> 			libata.dma=0	  Disable all PATA and SATA DMA
> 			libata.dma=1	  PATA and SATA Disk DMA only
> 			libata.dma=2	  ATAPI (CDROM) DMA only
> 			libata.dma=4	  Compact Flash DMA only
> 			Combinations also work, so libata.dma=3 enables DMA
> 			for disks and CDROMs, but not CFs.
>
> So, SSD is going to CFs. No surprise, of course. But if no dma is on -
haha, the speed of devise suffers well!
During bootup kernel says (in case of libata.dma={<=3}), that my SSD
(AAO-110L, 8Gb SSD-PAMM, Samsung) is in (!) PIO4 transfer data mode. It is
REALLY slow.

hdparm -tT /dev/sda
Cached reads: 370 MB/sec
Buffered reads: 2.3 MB/sec

And it is reading - do I have to talk 'bout writing?
Where to dig now, when the reason of problem seems 2 be localized?

2009/12/8 Andrew Squire <email address hidden>

> I had this issue on my EeePC 901. I took the following actions and have
> not *yet* seen the issue reappear:
>
> 1. Boot from 9.10 NBR Live CD
> 2. dd if=/dev/zero of=/dev/sda bs=1M
> 3. dd if=/dev/zero of=/dev/sdb bs=1M
> 4. install 9.10 NBR
> 5. Add kernal command "libata.dma=0" in GRUB2 config and rebuild GRUB2 menu
>
> NOTE: When I first got the issue I first tried steps 4. & 5. without
> doing 1. 2. 3. and it did not fix the issue.
>
> --
> SSD stall during boot
> https://bugs.launchpad.net/bugs/445852
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in The Linux Kernel: Confirmed
> Status in “linux” package in Ubuntu: Confirmed
>
> Bug description:
> In the Karmic beta I experience ssd stalls during the boot process.  It
> happens almost everytime before xsplash loads and happens again frequently
> between logging into gdm and the desktop loading.  When it happens during
> login I think it is making gnome time out on loading panel items as I get
> errors related to lots of panel items failing to load.  If I log out and
> back in again when the ssd isn't stalled the panel items load fine.
>
> When it happens the following messages appear before xplash (or in dmesg
> when it happens after gdm):
>
> ata2: lost interrupt (Status 0x58)
> ata2: drained 16384 bytes to clear DRQ.
> ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
> ata2.00: BMDMA stat 0x4
> ata2.00: cmd c8/00:40:cb:60:32/00:00:00:00:00/e0 tag 0 dma 32768 in
> res 58/00:40:cb:60:32/00:00:00:00:00/e0 Emask 0x2 (HSM violation)
> ata2.00: status: { DRDY DRQ }
> ata2: soft resetting link
> ata2.00: configured for UDMA/66
> ata2: EH complete
>
> I did not have this issue in jaunty with this hardware and I don't think it
> has happened once the system is fully loaded.  I am running karmic unr on an
> Acer Aspire One netbook.
>
> ProblemType: Bug
> AplayDevices:
>  **** List of PLAYBACK Hardware Devices ****
>  card 0: Intel [HDA Intel], device 0: ALC268 Analog [ALC268 Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> Architecture: i386
> ArecordDevices:
>  **** List of CAPTURE Hardware Devices ****
>  card 0: Intel [HDA Intel], device 0: ALC268 Analog [ALC268 Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> AudioDevicesInUse:
>  USER        PID ACCESS COMMAND
>  /dev/snd/controlC0:  luke       1990 F.... pulseaudio
> CRDA: Error: [Errno 2] No such file or directory
> Card0.Amixer.info:
>  Card hw:0 'Intel'/'HDA Intel at 0x58540000 irq 16'
>   Mixer name   : 'Realtek ALC268'
>   Components   : 'HDA:10ec0268,1025015b,00100101'
>   Controls      : 9
>   Simple ctrls  : 6
> CheckboxSubmission: 12ef539f3788bfbc46bc56b5c28128a6
> CheckboxSystem: c69722ecac764861be52925fa50b4dcc
> Date: Wed Oct  7 17:54:56 2009
> DistroRelease: Ubuntu 9.10
> HibernationDevice: RESUME=UUID=8d44b89b-2edb-4c02-a4be-94bd25b65081
> MachineType: Acer AOA110
> Package: linux-image-2.6.31-12-generic 2.6.31-12.40
> ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-12-generic
> root=UUID=039a096e-3486-4898-9eeb-44a705f8b7fd ro quiet splash elevator=noop
> usbcore.autosuspend=1
> ProcEnviron:
>  LANG=en_CA.UTF-8
>  SHELL=/bin/bash
> ProcVersionSignature: Ubuntu 2.6.31-12.40-generic
> RelatedPackageVersions: linux-firmware 1.21
> RfKill:
>  0: phy0: Wireless LAN
>        Soft blocked: no
>        Hard blocked: no
> SourcePackage: linux
> Tags:  ubuntu-unr
> Uname: Linux 2.6.31-12-generic i686
> XsessionErrors:
>  (gnome-settings-daemon:2006): GLib-CRITICAL **: g_propagate_error:
> assertion `src != NULL' failed
>  (gnome-settings-daemon:2006): GLib-CRITICAL **: g_propagate_error:
> assertion `src != NULL' failed
>  (nautilus:2092): Eel-CRITICAL **: eel_preferences_get_boolean: assertion
> `preferences_is_initialized ()' failed
>  (polkit-gnome-authentication-agent-1:2118): GLib-CRITICAL **:
> g_once_init_leave: assertion `initialization_value != 0' failed
>  (gnome-panel:2048): Gdk-WARNING **:
> /build/buildd/gtk+2.0-2.18.2/gdk/x11/gdkdrawable-x11.c:952 drawable is not a
> pixmap or window
> dmi.bios.date: 10/06/2008
> dmi.bios.vendor: Acer
> dmi.bios.version: v0.3309
> dmi.board.asset.tag: Base Board Asset Tag
> dmi.board.vendor: Acer
> dmi.board.version: Base Board Version
> dmi.chassis.type: 1
> dmi.chassis.vendor: Chassis Manufacturer
> dmi.chassis.version: Chassis Version
> dmi.modalias:
> dmi:bvnAcer:bvrv0.3309:bd10/06/2008:svnAcer:pnAOA110:pvr1:rvnAcer:rn:rvrBaseBoardVersion:cvnChassisManufacturer:ct1:cvrChassisVersion:
> dmi.product.name: AOA110
> dmi.product.version: 1
> dmi.sys.vendor: Acer
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/linux/+bug/445852/+subscribe
>