From: Tejun Heo <htejun@gmail.com>
To: "zhao, forrest" <forrest.zhao@intel.com>
Cc: Jeff Garzik <jgarzik@pobox.com>, linux-ide@vger.kernel.org
Subject: Re: [RFC] AHCI Command Completion Coalescing(CCC) proposal
Date: Fri, 09 Jun 2006 14:24:18 +0900 [thread overview]
Message-ID: <44890602.90002@gmail.com> (raw)
In-Reply-To: <1149825065.5721.22.camel@forrest26.sh.intel.com>
zhao, forrest wrote:
> On Fri, 2006-06-09 at 12:47 +0900, Tejun Heo wrote:
>> If we're gonna do it. EH needs only a few changes probably during
>> autopsy and report. Fixing up command issue path and implementing
>> command exclusion (NCQ vs. non-NCQ, sil24 does it in hardware, ahci
>> doesn't) will be a bit complex though.
>
> Would you please elaborate on command exclusion? Why NCQ commands need
> to be excluded from non-NCQ commands?
AHCI spec rev 1.1, sect 1.7. The last paragraph says.
"This multiple-use of the command list is achieved by the HBA only
moving its command list pointer when the BSY, DRQ, and ERR bits are
cleared by the device. System software is responsible to ensure that
queued and non-queued commands are not mixed in the command list."
--
tejun
next prev parent reply other threads:[~2006-06-09 5:24 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-06-08 7:30 [RFC] AHCI Command Completion Coalescing(CCC) proposal zhao, forrest
2006-06-08 15:01 ` Jeff Garzik
2006-06-09 2:27 ` zhao, forrest
2006-06-09 3:11 ` Another project for you... :) Jeff Garzik
2006-06-09 3:13 ` zhao, forrest
2006-06-09 22:29 ` Greg Freemyer
2006-06-09 23:44 ` Alan Cox
2006-06-09 3:43 ` [RFC] ATA host-protected area (HPA) device mapper? Jeff Garzik
2006-06-09 4:51 ` Matthew Frost
2006-06-14 8:01 ` Another project for you... :) zhao, forrest
2006-06-14 15:19 ` Randy.Dunlap
2006-06-15 7:59 ` zhao, forrest
2006-06-15 11:47 ` Jeff Garzik
2006-06-09 3:30 ` [RFC] AHCI Command Completion Coalescing(CCC) proposal Jeff Garzik
2006-06-09 3:39 ` zhao, forrest
2006-06-09 3:43 ` Tejun Heo
2006-06-09 3:47 ` Tejun Heo
2006-06-09 3:51 ` zhao, forrest
2006-06-09 4:12 ` Jeff Garzik
2006-06-09 5:24 ` Tejun Heo [this message]
2006-06-09 11:49 ` Jens Axboe
2006-06-09 3:53 ` Jeff Garzik
2006-06-09 3:52 ` Jeff Garzik
2006-06-09 11:49 ` Jens Axboe
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