Re: [git patch] atang tree: enhanced SSD detection

From: Jeff Garzik
Date: Tue Feb 23 2010 - 01:08:33 EST


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<bzolnier@xxxxxxxxx>
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<jeff@xxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz<bzolnier@xxxxxxxxx>

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



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