diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 20e03a7eb8b4..c2706047337f 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -116,7 +116,7 @@ config AHCI_ST
 
 config AHCI_IMX
 	tristate "Freescale i.MX AHCI SATA support"
-	depends on MFD_SYSCON
+	depends on MFD_SYSCON && (ARCH_MXC || COMPILE_TEST)
 	help
 	  This option enables support for the Freescale i.MX SoC's
 	  onboard AHCI SATA.
@@ -134,8 +134,7 @@ config AHCI_SUNXI
 
 config AHCI_XGENE
 	tristate "APM X-Gene 6.0Gbps AHCI SATA host controller support"
-	depends on ARM64 || COMPILE_TEST
-	select PHY_XGENE
+	depends on PHY_XGENE
 	help
 	 This option enables support for APM X-Gene SoC SATA host controller.
 
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 5a0bf8ed649b..71e15b73513d 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1164,9 +1164,9 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
 #endif
 
 static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
-			 struct ahci_host_priv *hpriv)
+				struct ahci_host_priv *hpriv)
 {
-	int nvec;
+	int rc, nvec;
 
 	if (hpriv->flags & AHCI_HFLAG_NO_MSI)
 		goto intx;
@@ -1183,12 +1183,19 @@ static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
 	if (nvec < n_ports)
 		goto single_msi;
 
-	nvec = pci_enable_msi_range(pdev, nvec, nvec);
-	if (nvec == -ENOSPC)
+	rc = pci_enable_msi_exact(pdev, nvec);
+	if (rc == -ENOSPC)
 		goto single_msi;
-	else if (nvec < 0)
+	else if (rc < 0)
 		goto intx;
 
+	/* fallback to single MSI mode if the controller enforced MRSM mode */
+	if (readl(hpriv->mmio + HOST_CTL) & HOST_MRSM) {
+		pci_disable_msi(pdev);
+		printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n");
+		goto single_msi;
+	}
+
 	return nvec;
 
 single_msi:
@@ -1232,18 +1239,18 @@ int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis)
 		return rc;
 
 	for (i = 0; i < host->n_ports; i++) {
-		const char* desc;
 		struct ahci_port_priv *pp = host->ports[i]->private_data;
 
-		/* pp is NULL for dummy ports */
-		if (pp)
-			desc = pp->irq_desc;
-		else
-			desc = dev_driver_string(host->dev);
+		/* Do not receive interrupts sent by dummy ports */
+		if (!pp) {
+			disable_irq(irq + i);
+			continue;
+		}
 
-		rc = devm_request_threaded_irq(host->dev,
-			irq + i, ahci_hw_interrupt, ahci_thread_fn, IRQF_SHARED,
-			desc, host->ports[i]);
+		rc = devm_request_threaded_irq(host->dev, irq + i,
+					       ahci_hw_interrupt,
+					       ahci_thread_fn, IRQF_SHARED,
+					       pp->irq_desc, host->ports[i]);
 		if (rc)
 			goto out_free_irqs;
 	}
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 51af275b3388..b5eb886da226 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -94,6 +94,7 @@ enum {
 	/* HOST_CTL bits */
 	HOST_RESET		= (1 << 0),  /* reset controller; self-clear */
 	HOST_IRQ_EN		= (1 << 1),  /* global IRQ enable */
+	HOST_MRSM		= (1 << 2),  /* MSI Revert to Single Message */
 	HOST_AHCI_EN		= (1 << 31), /* AHCI enabled */
 
 	/* HOST_CAP bits */
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c19734d96d7e..943cc8b83e59 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4224,8 +4224,10 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "PIONEER DVD-RW  DVR-216D",	NULL,	ATA_HORKAGE_NOSETXFER },
 
 	/* devices that don't properly handle queued TRIM commands */
-	{ "Micron_M500*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM, },
-	{ "Crucial_CT???M500SSD*",	NULL,	ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Micron_M500*",		"MU0[1-4]*",	ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Crucial_CT???M500SSD*",	"MU0[1-4]*",	ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Micron_M550*",		NULL,		ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Crucial_CT???M550SSD*",	NULL,		ATA_HORKAGE_NO_NCQ_TRIM, },
 
 	/*
 	 * Some WD SATA-I drives spin up and down erratically when the link
@@ -4792,21 +4794,26 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
 {
 	struct ata_queued_cmd *qc = NULL;
-	unsigned int i;
+	unsigned int i, tag;
 
 	/* no command while frozen */
 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
 		return NULL;
 
-	/* the last tag is reserved for internal command. */
-	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
-		if (!test_and_set_bit(i, &ap->qc_allocated)) {
-			qc = __ata_qc_from_tag(ap, i);
+	for (i = 0; i < ATA_MAX_QUEUE; i++) {
+		tag = (i + ap->last_tag + 1) % ATA_MAX_QUEUE;
+
+		/* the last tag is reserved for internal command. */
+		if (tag == ATA_TAG_INTERNAL)
+			continue;
+
+		if (!test_and_set_bit(tag, &ap->qc_allocated)) {
+			qc = __ata_qc_from_tag(ap, tag);
+			qc->tag = tag;
+			ap->last_tag = tag;
 			break;
 		}
-
-	if (qc)
-		qc->tag = i;
+	}
 
 	return qc;
 }
diff --git a/drivers/ata/pata_arasan_cf.c b/drivers/ata/pata_arasan_cf.c
index 6fac524c2f50..4edb1a81f63f 100644
--- a/drivers/ata/pata_arasan_cf.c
+++ b/drivers/ata/pata_arasan_cf.c
@@ -898,9 +898,12 @@ static int arasan_cf_probe(struct platform_device *pdev)
 
 	cf_card_detect(acdev, 0);
 
-	return ata_host_activate(host, acdev->irq, irq_handler, 0,
-			&arasan_cf_sht);
+	ret = ata_host_activate(host, acdev->irq, irq_handler, 0,
+				&arasan_cf_sht);
+	if (!ret)
+		return 0;
 
+	cf_exit(acdev);
 free_clk:
 	clk_put(acdev->clk);
 	return ret;
diff --git a/drivers/ata/pata_at91.c b/drivers/ata/pata_at91.c
index e9c87274a781..8a66f23af4c4 100644
--- a/drivers/ata/pata_at91.c
+++ b/drivers/ata/pata_at91.c
@@ -407,12 +407,13 @@ static int pata_at91_probe(struct platform_device *pdev)
 
 	host->private_data = info;
 
-	return ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
-			gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
-			irq_flags, &pata_at91_sht);
+	ret = ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
+				gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
+				irq_flags, &pata_at91_sht);
+	if (ret)
+		goto err_put;
 
-	if (!ret)
-		return 0;
+	return 0;
 
 err_put:
 	clk_put(info->mck);
diff --git a/drivers/ata/pata_samsung_cf.c b/drivers/ata/pata_samsung_cf.c
index a79566d05666..0610e78c8a2a 100644
--- a/drivers/ata/pata_samsung_cf.c
+++ b/drivers/ata/pata_samsung_cf.c
@@ -594,9 +594,13 @@ static int __init pata_s3c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, host);
 
-	return ata_host_activate(host, info->irq,
-			info->irq ? pata_s3c_irq : NULL,
-			0, &pata_s3c_sht);
+	ret = ata_host_activate(host, info->irq,
+				info->irq ? pata_s3c_irq : NULL,
+				0, &pata_s3c_sht);
+	if (ret)
+		goto stop_clk;
+
+	return 0;
 
 stop_clk:
 	clk_disable(info->clk);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 1de36be64df4..5ab4e3a76721 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -822,6 +822,7 @@ struct ata_port {
 	unsigned long		qc_allocated;
 	unsigned int		qc_active;
 	int			nr_active_links; /* #links with active qcs */
+	unsigned int		last_tag;	/* track next tag hw expects */
 
 	struct ata_link		link;		/* host default link */
 	struct ata_link		*slave_link;	/* see ata_slave_link_init() */