diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 2fc52407306c15c27b9fb0b11c2db4ef4641aeba..c69954023c2e7d8c235aace4b66a1d32298f36eb 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1364,6 +1364,40 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
 {}
 #endif
 
+/*
+ * On the Acer Aspire Switch Alpha 12, sometimes all SATA ports are detected
+ * as DUMMY, or detected but eventually get a "link down" and never get up
+ * again. When this happens, CAP.NP may hold a value of 0x00 or 0x01, and the
+ * port_map may hold a value of 0x00.
+ *
+ * Overriding CAP.NP to 0x02 and the port_map to 0x7 will reveal all 3 ports
+ * and can significantly reduce the occurrence of the problem.
+ *
+ * https://bugzilla.kernel.org/show_bug.cgi?id=189471
+ */
+static void acer_sa5_271_workaround(struct ahci_host_priv *hpriv,
+				    struct pci_dev *pdev)
+{
+	static const struct dmi_system_id sysids[] = {
+		{
+			.ident = "Acer Switch Alpha 12",
+			.matches = {
+				DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+				DMI_MATCH(DMI_PRODUCT_NAME, "Switch SA5-271")
+			},
+		},
+		{ }
+	};
+
+	if (dmi_check_system(sysids)) {
+		dev_info(&pdev->dev, "enabling Acer Switch Alpha 12 workaround\n");
+		if ((hpriv->saved_cap & 0xC734FF00) == 0xC734FF00) {
+			hpriv->port_map = 0x7;
+			hpriv->cap = 0xC734FF02;
+		}
+	}
+}
+
 #ifdef CONFIG_ARM64
 /*
  * Due to ERRATA#22536, ThunderX needs to handle HOST_IRQ_STAT differently.
@@ -1636,6 +1670,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 			 "online status unreliable, applying workaround\n");
 	}
 
+
+	/* Acer SA5-271 workaround modifies private_data */
+	acer_sa5_271_workaround(hpriv, pdev);
+
 	/* CAP.NP sometimes indicate the index of the last enabled
 	 * port, at other times, that of the last possible port, so
 	 * determining the maximum port number requires looking at
diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index aaa761b9081cc02a75792302c741f7b54ebd9823..cd2eab6aa92ea245e1a3dab839be7fe8aa938cdb 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -514,8 +514,9 @@ int ahci_platform_init_host(struct platform_device *pdev,
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq <= 0) {
-		dev_err(dev, "no irq\n");
-		return -EINVAL;
+		if (irq != -EPROBE_DEFER)
+			dev_err(dev, "no irq\n");
+		return irq;
 	}
 
 	hpriv->irq = irq;
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 2d83b8c7596567a020300d8dd1aeefeb33a6a055..e157a0e4441916b77b53c402741b74e124012cc9 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6800,7 +6800,7 @@ static int __init ata_parse_force_one(char **cur,
 	}
 
 	force_ent->port = simple_strtoul(id, &endp, 10);
-	if (p == endp || *endp != '\0') {
+	if (id == endp || *endp != '\0') {
 		*reason = "invalid port/link";
 		return -EINVAL;
 	}
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index b66bcda88320fefa399ac9653eca64d3045a6a96..3b2246dded74fbeed89d53f913c725ab6e5c0082 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -4067,7 +4067,6 @@ static int mv_platform_probe(struct platform_device *pdev)
 	struct ata_host *host;
 	struct mv_host_priv *hpriv;
 	struct resource *res;
-	void __iomem *mmio;
 	int n_ports = 0, irq = 0;
 	int rc;
 	int port;
@@ -4086,9 +4085,8 @@ static int mv_platform_probe(struct platform_device *pdev)
 	 * Get the register base first
 	 */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mmio = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(mmio))
-		return PTR_ERR(mmio);
+	if (res == NULL)
+		return -EINVAL;
 
 	/* allocate host */
 	if (pdev->dev.of_node) {
@@ -4132,7 +4130,12 @@ static int mv_platform_probe(struct platform_device *pdev)
 	hpriv->board_idx = chip_soc;
 
 	host->iomap = NULL;
-	hpriv->base = mmio - SATAHC0_REG_BASE;
+	hpriv->base = devm_ioremap(&pdev->dev, res->start,
+				   resource_size(res));
+	if (!hpriv->base)
+		return -ENOMEM;
+
+	hpriv->base -= SATAHC0_REG_BASE;
 
 	hpriv->clk = clk_get(&pdev->dev, NULL);
 	if (IS_ERR(hpriv->clk))
diff --git a/drivers/ata/sata_rcar.c b/drivers/ata/sata_rcar.c
index 5d38245a7a73a7cc4fa0d49255a52c7daead7886..b7939a2c1fab53ff2a94799a261d401c1c440f2e 100644
--- a/drivers/ata/sata_rcar.c
+++ b/drivers/ata/sata_rcar.c
@@ -890,7 +890,10 @@ static int sata_rcar_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "failed to get access to sata clock\n");
 		return PTR_ERR(priv->clk);
 	}
-	clk_prepare_enable(priv->clk);
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
 
 	host = ata_host_alloc(&pdev->dev, 1);
 	if (!host) {
@@ -970,8 +973,11 @@ static int sata_rcar_resume(struct device *dev)
 	struct ata_host *host = dev_get_drvdata(dev);
 	struct sata_rcar_priv *priv = host->private_data;
 	void __iomem *base = priv->base;
+	int ret;
 
-	clk_prepare_enable(priv->clk);
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
 
 	/* ack and mask */
 	iowrite32(0, base + SATAINTSTAT_REG);
@@ -988,8 +994,11 @@ static int sata_rcar_restore(struct device *dev)
 {
 	struct ata_host *host = dev_get_drvdata(dev);
 	struct sata_rcar_priv *priv = host->private_data;
+	int ret;
 
-	clk_prepare_enable(priv->clk);
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
 
 	sata_rcar_setup_port(host);