[PATCH] AHCI prefetch

From: Jeff Garzik
Date: Sat Mar 04 2006 - 12:32:46 EST



This patch has been sitting in my tmp directory for ages.

We should probably turn this on, though the practical difference is
probably minimal.


diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 4e96ec5..973a794 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -64,8 +64,10 @@ enum {
AHCI_PORT_PRIV_DMA_SZ = AHCI_CMD_SLOT_SZ + AHCI_CMD_TBL_SZ +
AHCI_RX_FIS_SZ,
AHCI_IRQ_ON_SG = (1 << 31),
+
AHCI_CMD_ATAPI = (1 << 5),
AHCI_CMD_WRITE = (1 << 6),
+ AHCI_CMD_PREFETCH = (1 << 7),

RX_FIS_D2H_REG = 0x40, /* offset of D2H Register FIS data */

@@ -533,7 +535,7 @@ static void ahci_qc_prep(struct ata_queu
if (qc->tf.flags & ATA_TFLAG_WRITE)
opts |= AHCI_CMD_WRITE;
if (is_atapi_taskfile(&qc->tf))
- opts |= AHCI_CMD_ATAPI;
+ opts |= AHCI_CMD_ATAPI | AHCI_CMD_PREFETCH;

pp->cmd_slot[0].opts = cpu_to_le32(opts);
pp->cmd_slot[0].status = 0;
-
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