Bugzilla Bug 178559

As from linux kernel version 2.6.22-rc1, a refactored suspend and resume
support for ata disks has been merged [1] [2]. Lack of feature on prior kernels
libata drivers and incorrect behavior on userland tools are causing anomalous
head parking noises on a considerably number of hard disks, as various bug
reports appeared in the web [3] [4]. This is not only an annoying problem but
it's considered a possible risk of reduced hard disk lifespan (especially for
laptop users). A page in the linux-ata home site has been set up in the to
assist userland init tools developers in the migration [5].

The following extract by Tejun Heo, the author of the concerning kernel
patches, illustrate the approach that should adopted in updated
shutdown(8)/halt(8) implementations.

>  * Check whether /sys/modules/libata/parameters/spindown_compat
>    exists.  If it does, write 0 to it.
>
>  * For each libata harddisk {
>        * Check whether /sys/class/scsi_disk/h:c:i:l/manage_start_stop
>          exists.  Iff it doesn't, synchronize cache and spin the disk
>          down as before.
>  }

[1]
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9666f4009c22f6520ac3fb8a19c9e32ab973e828
[2]
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=920a4b1038e442700a1cfac77ea7e20bd615a2c3
[3] https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.17/+bug/67810
[4] http://bugzilla.kernel.org/show_bug.cgi?id=7674
[5] http://linux-ata.org/shutdown.html

Reproducible: Always

Steps to Reproduce:
An affected system using libata on a kernel prior to 2.6.22rc1 and an
un-updated shutdown(8) implementation, shutting down.
Actual Results:  
Anomalous hard disk head parking noise.

Expected Results:  
Correct hard disk spindown.

A selectable kernel option to alleviate the problem on affected systems until
it's has been fully addressed by userland shutdown(8)/halt(8) implementations
has been also merged in 2.6.22rc1 . However, as stated by Tejun Heo, author of
the concerning patches:

> To accelerate shutdown(8) updates, if the compat mode is in use, this
> patch prints BIG FAT warning for five seconds during shutdown (the
> optimal interval to annoy the user just the right amount discovered by
> hours of tireless usability testing).

Please, continue in the pending bug. Thanks.

*** This bug has been marked as a duplicate of bug 174373 ***