hi,
The SATA spec defines DMA setup FIS auto-activate optimization for FPDMA
transfers. I had an attempt to add it, though my test doesn't show obvious
performance improvement (not worse too), I wonder why not add this feature?
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2c6aeda..53cc355 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2303,6 +2303,7 @@ static void ata_dev_config_ncq(struct ata_device *dev,
{
struct ata_port *ap = dev->link->ap;
int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
+ const u16 *id = dev->id;
if (!ata_id_has_ncq(dev->id)) {
desc[0] = '\0';
@@ -2317,6 +2318,9 @@ static void ata_dev_config_ncq(struct ata_device *dev,
dev->flags |= ATA_DFLAG_NCQ;
}
+ if (ata_id_has_daa(id))
+ ata_dev_set_feature(dev, SETFEATURES_SATA_ENABLE, SATA_DAA);
+
if (hdepth >= ddepth)
snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
else
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 9c75921..bb5b6ba 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -306,6 +306,7 @@ enum {
/* SETFEATURE Sector counts for SATA features */
SATA_AN = 0x05, /* Asynchronous Notification */
SATA_DIPM = 0x03, /* Device Initiated Power Management */
+ SATA_DAA = 0x02, /* DMA Setup FIS Auto-Activate */
/* feature values for SET_MAX */
ATA_SET_MAX_ADDR = 0x00,
@@ -525,6 +526,9 @@ static inline int ata_is_data(u8 prot)
#define ata_id_has_atapi_AN(id) \
( (((id)[76] != 0x0000) && ((id)[76] != 0xffff)) && \
((id)[78] & (1 << 5)) )
+#define ata_id_has_daa(id) \
+ ( (((id)[76] != 0x0000) && ((id)[76] != 0xffff)) && \
+ ((id)[78] & (1 << 2)) )
#define ata_id_iordy_disable(id) ((id)[ATA_ID_CAPABILITY] & (1 << 10))
#define ata_id_has_iordy(id) ((id)[ATA_ID_CAPABILITY] & (1 << 11))
#define ata_id_u32(id,n) \
--
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