On 02/21/2010 12:41 PM, Bartlomiej Zolnierkiewicz wrote:

DISCLAIMER: the fact of getting patches merged into atang tree means
that from now on they will be getting updates for changes happening
in atang tree and it should not be treated as an indication regarding
decisions taken by 'upstream' kernel trees


Improve SSD detection so block layer optimizations can be applied
to many more SSD devices.


The following changes since commit 17c619273d412ed7b6120e448f87b2329457fc90:
   Bartlomiej Zolnierkiewicz (1):
         pata_oldpiix: enable parallel scan

are available in the git repository at:

   git://git.kernel.org/pub/scm/linux/kernel/git/bart/misc.git atang-v4.7

Bartlomiej Zolnierkiewicz (1):
       libata: enhanced SSD detection

  drivers/ata/libata-core.c |    3 +++
  drivers/ata/libata-scsi.c |   18 ++++++++++--------
  include/linux/libata.h    |    1 +
  3 files changed, 14 insertions(+), 8 deletions(-)


commit ded92e0d01fbb7f27bec7a35606847a2547e95e0
Author: Bartlomiej Zolnierkiewicz[off-list ref]
Date:   Sun Feb 21 18:31:18 2010 +0100

     libata: enhanced SSD detection

     Many SSD devices predate or just don't implement non-rotational
     media type advertisement through the word 217 of the id block so
     check also the product id for 'SSD' substring to automatically
     detect SSD devices and apply relevant block layer optimizations.

     This is based on earlier Jeff Garzik's patch from April 2009:
     http://lkml.org/lkml/2009/4/7/495

     While at it:
     - cleanup ata_scsi_dev_config() a bit

     Tested with ASUS-PHISON SSD devices found in Asus Eee 901.

     Cc: Jeff Garzik[off-list ref]
     Signed-off-by: Bartlomiej Zolnierkiewicz[off-list ref]

Yes, I agree we need something like this.  I will review for atang 
dependencies, and then make sure it gets applied to upstream.

The previous discussion of this approach concluded weakly with "poor 
heuristic", but a better approach did not materialize.

One question, though:  why did you drop ata_id_is_ssd() test?

	Jeff