From: Tejun Heo <htejun@gmail.com>
To: Jeff Garzik <jeff@garzik.org>
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] ahci: enable prefetching for PACKET commands
Date: Sun, 12 Mar 2006 11:25:27 +0900 [thread overview]
Message-ID: <20060312022527.GA29870@htj.dyndns.org> (raw)
In-Reply-To: <44136C13.4020002@garzik.org>
Turn on AHCI_CMD_PREFETCH for PACKET commands. This hints the
controller that it can prefetch the CDB and the PRD entries. This
patch is originally from Jeff Garzik.
Signed-off-by: Tejun Heo <htejun@gmail.com>
---
Jeff, I'll send two flavors of this patch. The other one will enable
AHCI_CMD_PREFETCH for both ATA and ATAPI devices. I've tested both
cases on ICH7R.
ahci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 00dfdef..e97ab3e 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -66,6 +66,7 @@ enum {
AHCI_IRQ_ON_SG = (1 << 31),
AHCI_CMD_ATAPI = (1 << 5),
AHCI_CMD_WRITE = (1 << 6),
+ AHCI_CMD_PREFETCH = (1 << 7),
AHCI_CMD_RESET = (1 << 8),
AHCI_CMD_CLR_BUSY = (1 << 10),
@@ -631,7 +632,7 @@ static void ahci_qc_prep(struct ata_queu
if (qc->tf.flags & ATA_TFLAG_WRITE)
opts |= AHCI_CMD_WRITE;
if (is_atapi)
- opts |= AHCI_CMD_ATAPI;
+ opts |= AHCI_CMD_ATAPI | AHCI_CMD_PREFETCH;
ahci_fill_cmd_slot(pp, opts);
}
next prev parent reply other threads:[~2006-03-12 2:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-04 17:35 [PATCH] AHCI prefetch Jeff Garzik
2006-03-10 4:37 ` Tejun Heo
2006-03-12 0:32 ` Jeff Garzik
2006-03-12 2:25 ` Tejun Heo [this message]
2006-03-12 2:30 ` [PATCH] ahci: enable prefetching Tejun Heo
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