From 4b10e559277de490bf5c257a1e3264a2bf51404b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 12 Mar 2006 11:25:27 +0900 Subject: [PATCH] [PATCH] ahci: enable prefetching for PACKET commands 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 Signed-off-by: Jeff Garzik --- drivers/scsi/ahci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c index 00dfdefe2967..e97ab3e6de4d 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_queued_cmd *qc) 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); }