Messages in this thread Patch in this message | | | Date | Sun, 12 Mar 2006 11:25:27 +0900 | From | Tejun Heo <> | Subject | [PATCH] ahci: enable prefetching for PACKET commands |
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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>
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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); } - 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/
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