lkml.org 
[lkml]   [2007]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] sata_nv,ahci: add the ahci legacy mode support to sata_nv
peer chen wrote:
> I hope one of the following patches can be merged to 2.6.24.
> ==========================
> http://lkml.org/lkml/2007/10/8/93
> http://lkml.org/lkml/2007/9/25/20

Unfortunately I do not feel like this is the right course of action.

Experience from Intel platforms tells us that our users get very unhappy
when their silicon supports AHCI mode, but they are forced into using a
less-performant mode. A popular example is an <unnamed> OEM whose BIOS
had no method whatsoever for enabling AHCI -- didn't even program the
PCI BAR -- even though tests showed the AHCI mode worked just fine when
manually programmed.

AHCI is more likely to provide a /stable/ Serial ATA experience, because
the silicon deals primarily with sending and receiving FIS's, and not
much else. In constrast, experience has shown the legacy IDE interface
to be a less reliable method of SATA support. And certainly AHCI is
much, much faster with less per-command overhead.

Given that AHCI is both faster and more stable, I feel it is the best
policy to enable AHCI when the hardware supports it, regardless of PCI
class code (IDE, SATA, or RAID).


> Yes, I agree to set the 'swncq' as default for 2.6.24, after all, for
> our server customers, stability is far more important than the new
> feature no matter the problem is caused by drive or controller.

Agreed. Done!

Jeff




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-10-19 04:59    [W:0.055 / U:1.360 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site