aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRobert Hancock <hancockr@shaw.ca>2007-02-05 16:26:02 -0800
committerJeff Garzik <jeff@garzik.org>2007-02-09 17:39:39 -0500
commit382a6652e91b34d5480cfc0ed840c196650493d4 (patch)
tree53f42152bedf08a0135b010885703605e7b35e5f
parent5bd28a4b6efa73c5d033f3b86201c2c366b170cf (diff)
downloadlinux-2.6.34-ux500-382a6652e91b34d5480cfc0ed840c196650493d4.tar.gz
sata_nv: use ADMA for NODATA commands
Some problems showed up recently with cache flush commands timing out on sata_nv. Previously these commands were always handled by transitioning to legacy mode from ADMA mode first. The timeout problem was worked around already by a change to the interrupt handling code for legacy mode, but for non-data commands like these it appears we can handle them in ADMA mode, so the switch to legacy mode is not needed. This patch changes the behavior so that we use ADMA mode to submit interrupt-driven commands with ATA_PROT_NODATA protocol. In addition to avoiding the problem mentioned above entirely, this avoids the overhead of switching to legacy mode and back to ADMA mode for handling cache flushes. When handling non-DMA-mapped commands, we leave the APRD blank and clear the NV_CPB_CTL_APRD_VALID field in the CPB so the controller does not attempt to read it. Signed-off-by: Robert Hancock <hancockr@shaw.ca> Cc: Jeff Garzik <jeff@garzik.org> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
-rw-r--r--drivers/ata/sata_nv.c32
1 files changed, 25 insertions, 7 deletions
diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index 3dd5ca16a2b..19817b37616 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -1159,16 +1159,31 @@ static void nv_adma_fill_sg(struct ata_queued_cmd *qc, struct nv_adma_cpb *cpb)
cpb->next_aprd = cpu_to_le64(((u64)(pp->aprd_dma + NV_ADMA_SGTBL_SZ * qc->tag)));
}
+static int nv_adma_use_reg_mode(struct ata_queued_cmd *qc)
+{
+ struct nv_adma_port_priv *pp = qc->ap->private_data;
+
+ /* ADMA engine can only be used for non-ATAPI DMA commands,
+ or interrupt-driven no-data commands. */
+ if((pp->flags & NV_ADMA_ATAPI_SETUP_COMPLETE) ||
+ (qc->tf.flags & ATA_TFLAG_POLLING))
+ return 1;
+
+ if((qc->flags & ATA_QCFLAG_DMAMAP) ||
+ (qc->tf.protocol == ATA_PROT_NODATA))
+ return 0;
+
+ return 1;
+}
+
static void nv_adma_qc_prep(struct ata_queued_cmd *qc)
{
struct nv_adma_port_priv *pp = qc->ap->private_data;
struct nv_adma_cpb *cpb = &pp->cpb[qc->tag];
u8 ctl_flags = NV_CPB_CTL_CPB_VALID |
- NV_CPB_CTL_APRD_VALID |
NV_CPB_CTL_IEN;
- if (!(qc->flags & ATA_QCFLAG_DMAMAP) ||
- (pp->flags & NV_ADMA_ATAPI_SETUP_COMPLETE)) {
+ if (nv_adma_use_reg_mode(qc)) {
nv_adma_register_mode(qc->ap);
ata_qc_prep(qc);
return;
@@ -1188,7 +1203,11 @@ static void nv_adma_qc_prep(struct ata_queued_cmd *qc)
nv_adma_tf_to_cpb(&qc->tf, cpb->tf);
- nv_adma_fill_sg(qc, cpb);
+ if(qc->flags & ATA_QCFLAG_DMAMAP) {
+ nv_adma_fill_sg(qc, cpb);
+ ctl_flags |= NV_CPB_CTL_APRD_VALID;
+ } else
+ memset(&cpb->aprd[0], 0, sizeof(struct nv_adma_prd) * 5);
/* Be paranoid and don't let the device see NV_CPB_CTL_CPB_VALID until we are
finished filling in all of the contents */
@@ -1203,10 +1222,9 @@ static unsigned int nv_adma_qc_issue(struct ata_queued_cmd *qc)
VPRINTK("ENTER\n");
- if (!(qc->flags & ATA_QCFLAG_DMAMAP) ||
- (pp->flags & NV_ADMA_ATAPI_SETUP_COMPLETE)) {
+ if (nv_adma_use_reg_mode(qc)) {
/* use ATA register mode */
- VPRINTK("no dmamap or ATAPI, using ATA register mode: 0x%lx\n", qc->flags);
+ VPRINTK("using ATA register mode: 0x%lx\n", qc->flags);
nv_adma_register_mode(qc->ap);
return ata_qc_issue_prot(qc);
} else