[libata] add DMA setup FIS auto-activate feature

Hopefully results in fewer on-the-wire FIS's and no breakage.  We'll see!
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/ahci.c

@@ -2869,7 +2869,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	/* prepare host */
 	if (hpriv->cap & HOST_CAP_NCQ)
-		pi.flags |= ATA_FLAG_NCQ;
+		pi.flags |= ATA_FLAG_NCQ | ATA_FLAG_FPDMA_AA;
 
 	if (hpriv->cap & HOST_CAP_PMP)
 		pi.flags |= ATA_FLAG_PMP;

drivers/ata/libata-core.c

@@ -2299,29 +2299,49 @@ static inline u8 ata_dev_knobble(struct ata_device *dev)
 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
 }
 
-static void ata_dev_config_ncq(struct ata_device *dev,
+static int ata_dev_config_ncq(struct ata_device *dev,
 			       char *desc, size_t desc_sz)
 {
 	struct ata_port *ap = dev->link->ap;
 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
+	unsigned int err_mask;
+	char *aa_desc = "";
 
 	if (!ata_id_has_ncq(dev->id)) {
 		desc[0] = '\0';
-		return;
+		return 0;
 	}
 	if (dev->horkage & ATA_HORKAGE_NONCQ) {
 		snprintf(desc, desc_sz, "NCQ (not used)");
-		return;
+		return 0;
 	}
 	if (ap->flags & ATA_FLAG_NCQ) {
 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
 		dev->flags |= ATA_DFLAG_NCQ;
 	}
 
+	if (!(dev->horkage & ATA_HORKAGE_BROKEN_FPDMA_AA) &&
+		(ap->flags & ATA_FLAG_FPDMA_AA) &&
+		ata_id_has_fpdma_aa(dev->id)) {
+		err_mask = ata_dev_set_feature(dev, SETFEATURES_SATA_ENABLE,
+			SATA_FPDMA_AA);
+		if (err_mask) {
+			ata_dev_printk(dev, KERN_ERR, "failed to enable AA"
+				"(error_mask=0x%x)\n", err_mask);
+			if (err_mask != AC_ERR_DEV) {
+				dev->horkage |= ATA_HORKAGE_BROKEN_FPDMA_AA;
+				return -EIO;
+			}
+		} else
+			aa_desc = ", AA";
+	}
+
 	if (hdepth >= ddepth)
-		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
+		snprintf(desc, desc_sz, "NCQ (depth %d)%s", ddepth, aa_desc);
 	else
-		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
+		snprintf(desc, desc_sz, "NCQ (depth %d/%d)%s", hdepth,
+			ddepth, aa_desc);
+	return 0;
 }
 
 /**
@@ -2461,7 +2481,7 @@ int ata_dev_configure(struct ata_device *dev)
 
 		if (ata_id_has_lba(id)) {
 			const char *lba_desc;
-			char ncq_desc[20];
+			char ncq_desc[24];
 
 			lba_desc = "LBA";
 			dev->flags |= ATA_DFLAG_LBA;
@@ -2475,7 +2495,9 @@ int ata_dev_configure(struct ata_device *dev)
 			}
 
 			/* config NCQ */
-			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
+			rc = ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
+			if (rc)
+				return rc;
 
 			/* print device info to dmesg */
 			if (ata_msg_drv(ap) && print_info) {

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_FPDMA_AA		= 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_fpdma_aa(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)	\

include/linux/libata.h

@@ -190,6 +190,7 @@ enum {
 	ATA_FLAG_NO_POWEROFF_SPINDOWN = (1 << 11), /* don't spindown before poweroff */
 	ATA_FLAG_NO_HIBERNATE_SPINDOWN = (1 << 12), /* don't spindown before hibernation */
 	ATA_FLAG_DEBUGMSG	= (1 << 13),
+	ATA_FLAG_FPDMA_AA		= (1 << 14), /* driver supports Auto-Activate */
 	ATA_FLAG_IGN_SIMPLEX	= (1 << 15), /* ignore SIMPLEX */
 	ATA_FLAG_NO_IORDY	= (1 << 16), /* controller lacks iordy */
 	ATA_FLAG_ACPI_SATA	= (1 << 17), /* need native SATA ACPI layout */
@@ -386,6 +387,7 @@ enum {
 	ATA_HORKAGE_FIRMWARE_WARN = (1 << 12),	/* firmware update warning */
 	ATA_HORKAGE_1_5_GBPS	= (1 << 13),	/* force 1.5 Gbps */
 	ATA_HORKAGE_NOSETXFER	= (1 << 14),	/* skip SETXFER, SATA only */
+	ATA_HORKAGE_BROKEN_FPDMA_AA	= (1 << 15),	/* skip AA */
 
 	 /* DMA mask for user DMA control: User visible values; DO NOT
 	    renumber */