Merge branch 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata

Pull libata updates from Tejun Heo:

 - ahci grew runtime power management support so that the controller can
   be turned off if no devices are attached.

 - sata_via isn't dead yet.  It got hotplug support and more refined
   workaround for certain WD drives.

 - Misc cleanups.  There's a merge from for-4.5-fixes to avoid confusing
   conflicts in ahci PCI ID table.

* 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ata: ahci_xgene: dereferencing uninitialized pointer in probe
  AHCI: Remove obsolete Intel Lewisburg SATA RAID device IDs
  ata: sata_rcar: Use ARCH_RENESAS
  sata_via: Implement hotplug for VT6421
  sata_via: Apply WD workaround only when needed on VT6421
  ahci: Add runtime PM support for the host controller
  ahci: Add functions to manage runtime PM of AHCI ports
  ahci: Convert driver to use modern PM hooks
  ahci: Cache host controller version
  scsi: Drop runtime PM usage count after host is added
  scsi: Set request queue runtime PM status back to active on resume
  block: Add blk_set_runtime_active()
  ata: ahci_mvebu: add support for Armada 3700 variant
  libata: fix unbalanced spin_lock_irqsave/spin_unlock_irq() in ata_scsi_park_show()
  libata: support AHCI on OCTEON platform

Documentation/devicetree/bindings/ata/ahci-platform.txt

@@ -11,6 +11,7 @@ Required properties:
 - compatible        : compatible string, one of:
   - "allwinner,sun4i-a10-ahci"
   - "hisilicon,hisi-ahci"
+  - "cavium,octeon-7130-ahci"
   - "ibm,476gtr-ahci"
   - "marvell,armada-380-ahci"
   - "snps,dwc-ahci"

Documentation/devicetree/bindings/mips/cavium/sata-uctl.txt

@@ -0,0 +1,42 @@
+* UCTL SATA controller glue
+
+UCTL is the bridge unit between the I/O interconnect (an internal bus)
+and the SATA AHCI host controller (UAHC). It performs the following functions:
+	- provides interfaces for the applications to access the UAHC AHCI
+	  registers on the CN71XX I/O space.
+	- provides a bridge for UAHC to fetch AHCI command table entries and data
+	  buffers from Level 2 Cache.
+	- posts interrupts to the CIU.
+	- contains registers that:
+		- control the behavior of the UAHC
+		- control the clock/reset generation to UAHC
+		- control endian swapping for all UAHC registers and DMA accesses
+
+Properties:
+
+- compatible: "cavium,octeon-7130-sata-uctl"
+
+  Compatibility with the cn7130 SOC.
+
+- reg: The base address of the UCTL register bank.
+
+- #address-cells, #size-cells, ranges and dma-ranges must be present and hold
+	suitable values to map all child nodes.
+
+Example:
+
+	uctl@118006c000000 {
+		compatible = "cavium,octeon-7130-sata-uctl";
+		reg = <0x11800 0x6c000000 0x0 0x100>;
+		ranges; /* Direct mapping */
+		dma-ranges;
+		#address-cells = <2>;
+		#size-cells = <2>;
+
+		sata: sata@16c0000000000 {
+			compatible = "cavium,octeon-7130-ahci";
+			reg = <0x16c00 0x00000000 0x0 0x200>;
+			interrupt-parent = <&cibsata>;
+			interrupts = <2 4>; /* Bit: 2, level */
+		};
+	};

arch/mips/include/asm/octeon/cvmx.h

@@ -275,6 +275,11 @@ static inline void cvmx_write_csr(uint64_t csr_addr, uint64_t val)
 		cvmx_read64(CVMX_MIO_BOOT_BIST_STAT);
 }
 
+static inline void cvmx_writeq_csr(void __iomem *csr_addr, uint64_t val)
+{
+	cvmx_write_csr((__force uint64_t)csr_addr, val);
+}
+
 static inline void cvmx_write_io(uint64_t io_addr, uint64_t val)
 {
 	cvmx_write64(io_addr, val);
@@ -287,6 +292,10 @@ static inline uint64_t cvmx_read_csr(uint64_t csr_addr)
 	return val;
 }
 
+static inline uint64_t cvmx_readq_csr(void __iomem *csr_addr)
+{
+	return cvmx_read_csr((__force uint64_t) csr_addr);
+}
 
 static inline void cvmx_send_single(uint64_t data)
 {

block/blk-core.c

@@ -3529,6 +3529,30 @@ void blk_post_runtime_resume(struct request_queue *q, int err)
 	spin_unlock_irq(q->queue_lock);
 }
 EXPORT_SYMBOL(blk_post_runtime_resume);
+
+/**
+ * blk_set_runtime_active - Force runtime status of the queue to be active
+ * @q: the queue of the device
+ *
+ * If the device is left runtime suspended during system suspend the resume
+ * hook typically resumes the device and corrects runtime status
+ * accordingly. However, that does not affect the queue runtime PM status
+ * which is still "suspended". This prevents processing requests from the
+ * queue.
+ *
+ * This function can be used in driver's resume hook to correct queue
+ * runtime PM status and re-enable peeking requests from the queue. It
+ * should be called before first request is added to the queue.
+ */
+void blk_set_runtime_active(struct request_queue *q)
+{
+	spin_lock_irq(q->queue_lock);
+	q->rpm_status = RPM_ACTIVE;
+	pm_runtime_mark_last_busy(q->dev);
+	pm_request_autosuspend(q->dev);
+	spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_set_runtime_active);
 #endif
 
 int __init blk_dev_init(void)

drivers/ata/Kconfig

@@ -151,6 +151,15 @@ config AHCI_MVEBU
 
 	  If unsure, say N.
 
+config AHCI_OCTEON
+	tristate "Cavium Octeon Soc Serial ATA"
+	depends on SATA_AHCI_PLATFORM && CAVIUM_OCTEON_SOC
+	default y
+	help
+	  This option enables support for Cavium Octeon SoC Serial ATA.
+
+	  If unsure, say N.
+
 config AHCI_SUNXI
 	tristate "Allwinner sunxi AHCI SATA support"
 	depends on ARCH_SUNXI
@@ -355,7 +364,7 @@ config SATA_PROMISE
 
 config SATA_RCAR
 	tristate "Renesas R-Car SATA support"
-	depends on ARCH_SHMOBILE || COMPILE_TEST
+	depends on ARCH_RENESAS || COMPILE_TEST
 	help
 	  This option enables support for Renesas R-Car Serial ATA.
 

drivers/ata/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_AHCI_CEVA)		+= ahci_ceva.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_DA850)	+= ahci_da850.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_IMX)		+= ahci_imx.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_MVEBU)	+= ahci_mvebu.o libahci.o libahci_platform.o
+obj-$(CONFIG_AHCI_OCTEON)	+= ahci_octeon.o
 obj-$(CONFIG_AHCI_SUNXI)	+= ahci_sunxi.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_ST)		+= ahci_st.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_TEGRA)	+= ahci_tegra.o libahci.o libahci_platform.o

drivers/ata/ahci.c

@@ -85,6 +85,7 @@ enum board_ids {
 };
 
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
+static void ahci_remove_one(struct pci_dev *dev);
 static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
 				 unsigned long deadline);
 static int ahci_avn_hardreset(struct ata_link *link, unsigned int *class,
@@ -94,9 +95,13 @@ static bool is_mcp89_apple(struct pci_dev *pdev);
 static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
 				unsigned long deadline);
 #ifdef CONFIG_PM
-static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
-static int ahci_pci_device_resume(struct pci_dev *pdev);
+static int ahci_pci_device_runtime_suspend(struct device *dev);
+static int ahci_pci_device_runtime_resume(struct device *dev);
+#ifdef CONFIG_PM_SLEEP
+static int ahci_pci_device_suspend(struct device *dev);
+static int ahci_pci_device_resume(struct device *dev);
 #endif
+#endif /* CONFIG_PM */
 
 static struct scsi_host_template ahci_sht = {
 	AHCI_SHT("ahci"),
@@ -371,15 +376,11 @@ static const struct pci_device_id ahci_pci_tbl[] = {
 	{ PCI_VDEVICE(INTEL, 0x2826), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0x2827), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa182), board_ahci }, /* Lewisburg AHCI*/
-	{ PCI_VDEVICE(INTEL, 0xa184), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa186), board_ahci }, /* Lewisburg RAID*/
-	{ PCI_VDEVICE(INTEL, 0xa18e), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa1d2), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa1d6), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa202), board_ahci }, /* Lewisburg AHCI*/
-	{ PCI_VDEVICE(INTEL, 0xa204), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa206), board_ahci }, /* Lewisburg RAID*/
-	{ PCI_VDEVICE(INTEL, 0xa20e), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa252), board_ahci }, /* Lewisburg RAID*/
 	{ PCI_VDEVICE(INTEL, 0xa256), board_ahci }, /* Lewisburg RAID*/
 
@@ -563,16 +564,20 @@ static const struct pci_device_id ahci_pci_tbl[] = {
 	{ }	/* terminate list */
 };
 
+static const struct dev_pm_ops ahci_pci_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ahci_pci_device_suspend, ahci_pci_device_resume)
+	SET_RUNTIME_PM_OPS(ahci_pci_device_runtime_suspend,
+			   ahci_pci_device_runtime_resume, NULL)
+};
 
 static struct pci_driver ahci_pci_driver = {
 	.name			= DRV_NAME,
 	.id_table		= ahci_pci_tbl,
 	.probe			= ahci_init_one,
-	.remove			= ata_pci_remove_one,
-#ifdef CONFIG_PM
-	.suspend		= ahci_pci_device_suspend,
-	.resume			= ahci_pci_device_resume,
-#endif
+	.remove			= ahci_remove_one,
+	.driver = {
+		.pm		= &ahci_pci_pm_ops,
+	},
 };
 
 #if defined(CONFIG_PATA_MARVELL) || defined(CONFIG_PATA_MARVELL_MODULE)
@@ -801,42 +806,66 @@ static int ahci_avn_hardreset(struct ata_link *link, unsigned int *class,
 
 
 #ifdef CONFIG_PM
-static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
+static void ahci_pci_disable_interrupts(struct ata_host *host)
 {
-	struct ata_host *host = pci_get_drvdata(pdev);
 	struct ahci_host_priv *hpriv = host->private_data;
 	void __iomem *mmio = hpriv->mmio;
 	u32 ctl;
 
-	if (mesg.event & PM_EVENT_SUSPEND &&
-	    hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
-		dev_err(&pdev->dev,
-			"BIOS update required for suspend/resume\n");
-		return -EIO;
-	}
+	/* AHCI spec rev1.1 section 8.3.3:
+	 * Software must disable interrupts prior to requesting a
+	 * transition of the HBA to D3 state.
+	 */
+	ctl = readl(mmio + HOST_CTL);
+	ctl &= ~HOST_IRQ_EN;
+	writel(ctl, mmio + HOST_CTL);
+	readl(mmio + HOST_CTL); /* flush */
+}
 
-	if (mesg.event & PM_EVENT_SLEEP) {
-		/* AHCI spec rev1.1 section 8.3.3:
-		 * Software must disable interrupts prior to requesting a
-		 * transition of the HBA to D3 state.
-		 */
-		ctl = readl(mmio + HOST_CTL);
-		ctl &= ~HOST_IRQ_EN;
-		writel(ctl, mmio + HOST_CTL);
-		readl(mmio + HOST_CTL); /* flush */
-	}
+static int ahci_pci_device_runtime_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ata_host *host = pci_get_drvdata(pdev);
 
-	return ata_pci_device_suspend(pdev, mesg);
+	ahci_pci_disable_interrupts(host);
+	return 0;
 }
 
-static int ahci_pci_device_resume(struct pci_dev *pdev)
+static int ahci_pci_device_runtime_resume(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct ata_host *host = pci_get_drvdata(pdev);
 	int rc;
 
-	rc = ata_pci_device_do_resume(pdev);
+	rc = ahci_pci_reset_controller(host);
 	if (rc)
 		return rc;
+	ahci_pci_init_controller(host);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ahci_pci_device_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ata_host *host = pci_get_drvdata(pdev);
+	struct ahci_host_priv *hpriv = host->private_data;
+
+	if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
+		dev_err(&pdev->dev,
+			"BIOS update required for suspend/resume\n");
+		return -EIO;
+	}
+
+	ahci_pci_disable_interrupts(host);
+	return ata_host_suspend(host, PMSG_SUSPEND);
+}
+
+static int ahci_pci_device_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ata_host *host = pci_get_drvdata(pdev);
+	int rc;
 
 	/* Apple BIOS helpfully mangles the registers on resume */
 	if (is_mcp89_apple(pdev))
@@ -856,6 +885,8 @@ static int ahci_pci_device_resume(struct pci_dev *pdev)
 }
 #endif
 
+#endif /* CONFIG_PM */
+
 static int ahci_configure_dma_masks(struct pci_dev *pdev, int using_dac)
 {
 	int rc;
@@ -1718,7 +1749,18 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_master(pdev);
 
-	return ahci_host_activate(host, &ahci_sht);
+	rc = ahci_host_activate(host, &ahci_sht);
+	if (rc)
+		return rc;
+
+	pm_runtime_put_noidle(&pdev->dev);
+	return 0;
+}
+
+static void ahci_remove_one(struct pci_dev *pdev)
+{
+	pm_runtime_get_noresume(&pdev->dev);
+	ata_pci_remove_one(pdev);
 }
 
 module_pci_driver(ahci_pci_driver);

drivers/ata/ahci.h

@@ -335,6 +335,7 @@ struct ahci_host_priv {
 	void __iomem *		mmio;		/* bus-independent mem map */
 	u32			cap;		/* cap to use */
 	u32			cap2;		/* cap2 to use */
+	u32			version;	/* cached version */
 	u32			port_map;	/* port map to use */
 	u32			saved_cap;	/* saved initial cap */
 	u32			saved_cap2;	/* saved initial cap2 */

drivers/ata/ahci_mvebu.c

@@ -112,12 +112,15 @@ static int ahci_mvebu_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
-	dram = mv_mbus_dram_info();
-	if (!dram)
-		return -ENODEV;
+	if (of_device_is_compatible(pdev->dev.of_node,
+				    "marvell,armada-380-ahci")) {
+		dram = mv_mbus_dram_info();
+		if (!dram)
+			return -ENODEV;
 
-	ahci_mvebu_mbus_config(hpriv, dram);
-	ahci_mvebu_regret_option(hpriv);
+		ahci_mvebu_mbus_config(hpriv, dram);
+		ahci_mvebu_regret_option(hpriv);
+	}
 
 	rc = ahci_platform_init_host(pdev, hpriv, &ahci_mvebu_port_info,
 				     &ahci_platform_sht);
@@ -133,6 +136,7 @@ disable_resources:
 
 static const struct of_device_id ahci_mvebu_of_match[] = {
 	{ .compatible = "marvell,armada-380-ahci", },
+	{ .compatible = "marvell,armada-3700-ahci", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, ahci_mvebu_of_match);

drivers/ata/ahci_octeon.c

@@ -0,0 +1,105 @@
+/*
+ * SATA glue for Cavium Octeon III SOCs.
+ *
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2010-2015 Cavium Networks
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/bitfield.h>
+
+#define CVMX_SATA_UCTL_SHIM_CFG		0xE8
+
+#define SATA_UCTL_ENDIAN_MODE_BIG	1
+#define SATA_UCTL_ENDIAN_MODE_LITTLE	0
+#define SATA_UCTL_ENDIAN_MODE_MASK	3
+
+#define SATA_UCTL_DMA_ENDIAN_MODE_SHIFT	8
+#define SATA_UCTL_CSR_ENDIAN_MODE_SHIFT	0
+#define SATA_UCTL_DMA_READ_CMD_SHIFT	12
+
+static int ahci_octeon_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct resource *res;
+	void __iomem *base;
+	u64 cfg;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Platform resource[0] is missing\n");
+		return -ENODEV;
+	}
+
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	cfg = cvmx_readq_csr(base + CVMX_SATA_UCTL_SHIM_CFG);
+
+	cfg &= ~(SATA_UCTL_ENDIAN_MODE_MASK << SATA_UCTL_DMA_ENDIAN_MODE_SHIFT);
+	cfg &= ~(SATA_UCTL_ENDIAN_MODE_MASK << SATA_UCTL_CSR_ENDIAN_MODE_SHIFT);
+
+#ifdef __BIG_ENDIAN
+	cfg |= SATA_UCTL_ENDIAN_MODE_BIG << SATA_UCTL_DMA_ENDIAN_MODE_SHIFT;
+	cfg |= SATA_UCTL_ENDIAN_MODE_BIG << SATA_UCTL_CSR_ENDIAN_MODE_SHIFT;
+#else
+	cfg |= SATA_UCTL_ENDIAN_MODE_LITTLE << SATA_UCTL_DMA_ENDIAN_MODE_SHIFT;
+	cfg |= SATA_UCTL_ENDIAN_MODE_LITTLE << SATA_UCTL_CSR_ENDIAN_MODE_SHIFT;
+#endif
+
+	cfg |= 1 << SATA_UCTL_DMA_READ_CMD_SHIFT;
+
+	cvmx_writeq_csr(base + CVMX_SATA_UCTL_SHIM_CFG, cfg);
+
+	if (!node) {
+		dev_err(dev, "no device node, failed to add octeon sata\n");
+		return -ENODEV;
+	}
+
+	ret = of_platform_populate(node, NULL, NULL, dev);
+	if (ret) {
+		dev_err(dev, "failed to add ahci-platform core\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ahci_octeon_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static const struct of_device_id octeon_ahci_match[] = {
+	{ .compatible = "cavium,octeon-7130-sata-uctl", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, octeon_ahci_match);
+
+static struct platform_driver ahci_octeon_driver = {
+	.probe          = ahci_octeon_probe,
+	.remove         = ahci_octeon_remove,
+	.driver         = {
+		.name   = "octeon-ahci",
+		.of_match_table = octeon_ahci_match,
+	},
+};
+
+module_platform_driver(ahci_octeon_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cavium, Inc. <support@cavium.com>");
+MODULE_DESCRIPTION("Cavium Inc. sata config.");

drivers/ata/ahci_platform.c

@@ -76,6 +76,7 @@ static const struct of_device_id ahci_of_match[] = {
 	{ .compatible = "ibm,476gtr-ahci", },
 	{ .compatible = "snps,dwc-ahci", },
 	{ .compatible = "hisilicon,hisi-ahci", },
+	{ .compatible = "cavium,octeon-7130-ahci", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ahci_of_match);

drivers/ata/ahci_xgene.c

@@ -821,9 +821,9 @@ static int xgene_ahci_probe(struct platform_device *pdev)
 				dev_warn(&pdev->dev, "%s: Error reading device info. Assume version1\n",
 					__func__);
 				version = XGENE_AHCI_V1;
-			}
-			if (info->valid & ACPI_VALID_CID)
+			} else if (info->valid & ACPI_VALID_CID) {
 				version = XGENE_AHCI_V2;
+			}
 		}
 	}
 #endif

drivers/ata/libahci.c

@@ -225,6 +225,31 @@ static void ahci_enable_ahci(void __iomem *mmio)
 	WARN_ON(1);
 }
 
+/**
+ *	ahci_rpm_get_port - Make sure the port is powered on
+ *	@ap: Port to power on
+ *
+ *	Whenever there is need to access the AHCI host registers outside of
+ *	normal execution paths, call this function to make sure the host is
+ *	actually powered on.
+ */
+static int ahci_rpm_get_port(struct ata_port *ap)
+{
+	return pm_runtime_get_sync(ap->dev);
+}
+
+/**
+ *	ahci_rpm_put_port - Undoes ahci_rpm_get_port()
+ *	@ap: Port to power down
+ *
+ *	Undoes ahci_rpm_get_port() and possibly powers down the AHCI host
+ *	if it has no more active users.
+ */
+static void ahci_rpm_put_port(struct ata_port *ap)
+{
+	pm_runtime_put(ap->dev);
+}
+
 static ssize_t ahci_show_host_caps(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
@@ -251,9 +276,8 @@ static ssize_t ahci_show_host_version(struct device *dev,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct ata_port *ap = ata_shost_to_port(shost);
 	struct ahci_host_priv *hpriv = ap->host->private_data;
-	void __iomem *mmio = hpriv->mmio;
 
-	return sprintf(buf, "%x\n", readl(mmio + HOST_VERSION));
+	return sprintf(buf, "%x\n", hpriv->version);
 }
 
 static ssize_t ahci_show_port_cmd(struct device *dev,
@@ -262,8 +286,13 @@ static ssize_t ahci_show_port_cmd(struct device *dev,
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct ata_port *ap = ata_shost_to_port(shost);
 	void __iomem *port_mmio = ahci_port_base(ap);
+	ssize_t ret;
+
+	ahci_rpm_get_port(ap);
+	ret = sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));
+	ahci_rpm_put_port(ap);
 
-	return sprintf(buf, "%x\n", readl(port_mmio + PORT_CMD));
+	return ret;
 }
 
 static ssize_t ahci_read_em_buffer(struct device *dev,
@@ -279,17 +308,20 @@ static ssize_t ahci_read_em_buffer(struct device *dev,
 	size_t count;
 	int i;
 
+	ahci_rpm_get_port(ap);
 	spin_lock_irqsave(ap->lock, flags);
 
 	em_ctl = readl(mmio + HOST_EM_CTL);
 	if (!(ap->flags & ATA_FLAG_EM) || em_ctl & EM_CTL_XMT ||
 	    !(hpriv->em_msg_type & EM_MSG_TYPE_SGPIO)) {
 		spin_unlock_irqrestore(ap->lock, flags);
+		ahci_rpm_put_port(ap);
 		return -EINVAL;
 	}
 
 	if (!(em_ctl & EM_CTL_MR)) {
 		spin_unlock_irqrestore(ap->lock, flags);
+		ahci_rpm_put_port(ap);
 		return -EAGAIN;
 	}
 
@@ -317,6 +349,7 @@ static ssize_t ahci_read_em_buffer(struct device *dev,
 	}
 
 	spin_unlock_irqrestore(ap->lock, flags);
+	ahci_rpm_put_port(ap);
 
 	return i;
 }
@@ -341,11 +374,13 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
 	    size % 4 || size > hpriv->em_buf_sz)
 		return -EINVAL;
 
+	ahci_rpm_get_port(ap);
 	spin_lock_irqsave(ap->lock, flags);
 
 	em_ctl = readl(mmio + HOST_EM_CTL);
 	if (em_ctl & EM_CTL_TM) {
 		spin_unlock_irqrestore(ap->lock, flags);
+		ahci_rpm_put_port(ap);
 		return -EBUSY;
 	}
 
@@ -358,6 +393,7 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
 	writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
 
 	spin_unlock_irqrestore(ap->lock, flags);
+	ahci_rpm_put_port(ap);
 
 	return size;
 }
@@ -371,7 +407,9 @@ static ssize_t ahci_show_em_supported(struct device *dev,
 	void __iomem *mmio = hpriv->mmio;
 	u32 em_ctl;
 
+	ahci_rpm_get_port(ap);
 	em_ctl = readl(mmio + HOST_EM_CTL);
+	ahci_rpm_put_port(ap);
 
 	return sprintf(buf, "%s%s%s%s\n",
 		       em_ctl & EM_CTL_LED ? "led " : "",
@@ -509,6 +547,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
 	/* record values to use during operation */
 	hpriv->cap = cap;
 	hpriv->cap2 = cap2;
+	hpriv->version = readl(mmio + HOST_VERSION);
 	hpriv->port_map = port_map;
 
 	if (!hpriv->start_engine)
@@ -1014,6 +1053,7 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
 	else
 		return -EINVAL;
 
+	ahci_rpm_get_port(ap);
 	spin_lock_irqsave(ap->lock, flags);
 
 	/*
@@ -1023,6 +1063,7 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
 	em_ctl = readl(mmio + HOST_EM_CTL);
 	if (em_ctl & EM_CTL_TM) {
 		spin_unlock_irqrestore(ap->lock, flags);
+		ahci_rpm_put_port(ap);
 		return -EBUSY;
 	}
 
@@ -1050,6 +1091,8 @@ static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
 	emp->led_state = state;
 
 	spin_unlock_irqrestore(ap->lock, flags);
+	ahci_rpm_put_port(ap);
+
 	return size;
 }
 
@@ -2215,6 +2258,8 @@ static void ahci_pmp_detach(struct ata_port *ap)
 
 int ahci_port_resume(struct ata_port *ap)
 {
+	ahci_rpm_get_port(ap);
+
 	ahci_power_up(ap);
 	ahci_start_port(ap);
 
@@ -2241,6 +2286,7 @@ static int ahci_port_suspend(struct ata_port *ap, pm_message_t mesg)
 		ata_port_freeze(ap);
 	}
 
+	ahci_rpm_put_port(ap);
 	return rc;
 }
 #endif
@@ -2356,11 +2402,10 @@ static void ahci_port_stop(struct ata_port *ap)
 void ahci_print_info(struct ata_host *host, const char *scc_s)
 {
 	struct ahci_host_priv *hpriv = host->private_data;
-	void __iomem *mmio = hpriv->mmio;
 	u32 vers, cap, cap2, impl, speed;
 	const char *speed_s;
 
-	vers = readl(mmio + HOST_VERSION);
+	vers = hpriv->version;
 	cap = hpriv->cap;
 	cap2 = hpriv->cap2;
 	impl = hpriv->port_map;

drivers/ata/libata-scsi.c

@@ -174,13 +174,13 @@ static ssize_t ata_scsi_park_show(struct device *device,
 	struct ata_port *ap;
 	struct ata_link *link;
 	struct ata_device *dev;
-	unsigned long flags, now;
+	unsigned long now;
 	unsigned int uninitialized_var(msecs);
 	int rc = 0;
 
 	ap = ata_shost_to_port(sdev->host);
 
-	spin_lock_irqsave(ap->lock, flags);
+	spin_lock_irq(ap->lock);
 	dev = ata_scsi_find_dev(ap, sdev);
 	if (!dev) {
 		rc = -ENODEV;

drivers/ata/sata_via.c

@@ -61,6 +61,7 @@ enum {
 	SATA_CHAN_ENAB		= 0x40, /* SATA channel enable */
 	SATA_INT_GATE		= 0x41, /* SATA interrupt gating */
 	SATA_NATIVE_MODE	= 0x42, /* Native mode enable */
+	SVIA_MISC_3		= 0x46,	/* Miscellaneous Control III */
 	PATA_UDMA_TIMING	= 0xB3, /* PATA timing for DMA/ cable detect */
 	PATA_PIO_TIMING		= 0xAB, /* PATA timing register */
 
@@ -71,9 +72,18 @@ enum {
 	NATIVE_MODE_ALL		= (1 << 7) | (1 << 6) | (1 << 5) | (1 << 4),
 
 	SATA_EXT_PHY		= (1 << 6), /* 0==use PATA, 1==ext phy */
+
+	SATA_HOTPLUG		= (1 << 5), /* enable IRQ on hotplug */
+};
+
+struct svia_priv {
+	bool			wd_workaround;
 };
 
 static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
+#ifdef CONFIG_PM_SLEEP
+static int svia_pci_device_resume(struct pci_dev *pdev);
+#endif
 static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
 static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int vt8251_scr_read(struct ata_link *link, unsigned int scr, u32 *val);
@@ -85,6 +95,7 @@ static void vt6420_bmdma_start(struct ata_queued_cmd *qc);
 static int vt6421_pata_cable_detect(struct ata_port *ap);
 static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev);
 static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev);
+static void vt6421_error_handler(struct ata_port *ap);
 
 static const struct pci_device_id svia_pci_tbl[] = {
 	{ PCI_VDEVICE(VIA, 0x5337), vt6420 },
@@ -105,7 +116,7 @@ static struct pci_driver svia_pci_driver = {
 	.probe			= svia_init_one,
 #ifdef CONFIG_PM_SLEEP
 	.suspend		= ata_pci_device_suspend,
-	.resume			= ata_pci_device_resume,
+	.resume			= svia_pci_device_resume,
 #endif
 	.remove			= ata_pci_remove_one,
 };
@@ -137,6 +148,7 @@ static struct ata_port_operations vt6421_sata_ops = {
 	.inherits		= &svia_base_ops,
 	.scr_read		= svia_scr_read,
 	.scr_write		= svia_scr_write,
+	.error_handler		= vt6421_error_handler,
 };
 
 static struct ata_port_operations vt8251_ops = {
@@ -536,7 +548,67 @@ static int vt8251_prepare_host(struct pci_dev *pdev, struct ata_host **r_host)
 	return 0;
 }
 
-static void svia_configure(struct pci_dev *pdev, int board_id)
+static void svia_wd_fix(struct pci_dev *pdev)
+{
+	u8 tmp8;
+
+	pci_read_config_byte(pdev, 0x52, &tmp8);
+	pci_write_config_byte(pdev, 0x52, tmp8 | BIT(2));
+}
+
+static irqreturn_t vt6421_interrupt(int irq, void *dev_instance)
+{
+	struct ata_host *host = dev_instance;
+	irqreturn_t rc = ata_bmdma_interrupt(irq, dev_instance);
+
+	/* if the IRQ was not handled, it might be a hotplug IRQ */
+	if (rc != IRQ_HANDLED) {
+		u32 serror;
+		unsigned long flags;
+
+		spin_lock_irqsave(&host->lock, flags);
+		/* check for hotplug on port 0 */
+		svia_scr_read(&host->ports[0]->link, SCR_ERROR, &serror);
+		if (serror & SERR_PHYRDY_CHG) {
+			ata_ehi_hotplugged(&host->ports[0]->link.eh_info);
+			ata_port_freeze(host->ports[0]);
+			rc = IRQ_HANDLED;
+		}
+		/* check for hotplug on port 1 */
+		svia_scr_read(&host->ports[1]->link, SCR_ERROR, &serror);
+		if (serror & SERR_PHYRDY_CHG) {
+			ata_ehi_hotplugged(&host->ports[1]->link.eh_info);
+			ata_port_freeze(host->ports[1]);
+			rc = IRQ_HANDLED;
+		}
+		spin_unlock_irqrestore(&host->lock, flags);
+	}
+
+	return rc;
+}
+
+static void vt6421_error_handler(struct ata_port *ap)
+{
+	struct svia_priv *hpriv = ap->host->private_data;
+	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+	u32 serror;
+
+	/* see svia_configure() for description */
+	if (!hpriv->wd_workaround) {
+		svia_scr_read(&ap->link, SCR_ERROR, &serror);
+		if (serror == 0x1000500) {
+			ata_port_warn(ap, "Incompatible drive: enabling workaround. This slows down transfer rate to ~60 MB/s");
+			svia_wd_fix(pdev);
+			hpriv->wd_workaround = true;
+			ap->link.eh_context.i.flags |= ATA_EHI_QUIET;
+		}
+	}
+
+	ata_sff_error_handler(ap);
+}
+
+static void svia_configure(struct pci_dev *pdev, int board_id,
+			   struct svia_priv *hpriv)
 {
 	u8 tmp8;
 
@@ -572,6 +644,16 @@ static void svia_configure(struct pci_dev *pdev, int board_id)
 		pci_write_config_byte(pdev, SATA_NATIVE_MODE, tmp8);
 	}
 
+	/* enable IRQ on hotplug */
+	pci_read_config_byte(pdev, SVIA_MISC_3, &tmp8);
+	if ((tmp8 & SATA_HOTPLUG) != SATA_HOTPLUG) {
+		dev_dbg(&pdev->dev,
+			"enabling SATA hotplug (0x%x)\n",
+			(int) tmp8);
+		tmp8 |= SATA_HOTPLUG;
+		pci_write_config_byte(pdev, SVIA_MISC_3, tmp8);
+	}
+
 	/*
 	 * vt6420/1 has problems talking to some drives.  The following
 	 * is the fix from Joseph Chan <JosephChan@via.com.tw>.
@@ -593,11 +675,15 @@ static void svia_configure(struct pci_dev *pdev, int board_id)
 	 * https://bugzilla.kernel.org/show_bug.cgi?id=15173
 	 * http://article.gmane.org/gmane.linux.ide/46352
 	 * http://thread.gmane.org/gmane.linux.kernel/1062139
+	 *
+	 * As the fix slows down data transfer, apply it only if the error
+	 * actually appears - see vt6421_error_handler()
+	 * Apply the fix always on vt6420 as we don't know if SCR_ERROR can be
+	 * read safely.
 	 */
-	if (board_id == vt6420 || board_id == vt6421) {
-		pci_read_config_byte(pdev, 0x52, &tmp8);
-		tmp8 |= 1 << 2;
-		pci_write_config_byte(pdev, 0x52, tmp8);
+	if (board_id == vt6420) {
+		svia_wd_fix(pdev);
+		hpriv->wd_workaround = true;
 	}
 }
 
@@ -608,6 +694,7 @@ static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ata_host *host = NULL;
 	int board_id = (int) ent->driver_data;
 	const unsigned *bar_sizes;
+	struct svia_priv *hpriv;
 
 	ata_print_version_once(&pdev->dev, DRV_VERSION);
 
@@ -647,11 +734,39 @@ static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (rc)
 		return rc;
 
-	svia_configure(pdev, board_id);
+	hpriv = devm_kzalloc(&pdev->dev, sizeof(*hpriv), GFP_KERNEL);
+	if (!hpriv)
+		return -ENOMEM;
+	host->private_data = hpriv;
+
+	svia_configure(pdev, board_id, hpriv);
 
 	pci_set_master(pdev);
-	return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
-				 IRQF_SHARED, &svia_sht);
+	if (board_id == vt6421)
+		return ata_host_activate(host, pdev->irq, vt6421_interrupt,
+					 IRQF_SHARED, &svia_sht);
+	else
+		return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
+					 IRQF_SHARED, &svia_sht);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int svia_pci_device_resume(struct pci_dev *pdev)
+{
+	struct ata_host *host = pci_get_drvdata(pdev);
+	struct svia_priv *hpriv = host->private_data;
+	int rc;
+
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
+
+	if (hpriv->wd_workaround)
+		svia_wd_fix(pdev);
+	ata_host_resume(host);
+
+	return 0;
 }
+#endif
 
 module_pci_driver(svia_pci_driver);

drivers/scsi/hosts.c

@@ -250,6 +250,12 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 	if (error)
 		goto out_destroy_freelist;
 
+	/*
+	 * Increase usage count temporarily here so that calling
+	 * scsi_autopm_put_host() will trigger runtime idle if there is
+	 * nothing else preventing suspending the device.
+	 */
+	pm_runtime_get_noresume(&shost->shost_gendev);
 	pm_runtime_set_active(&shost->shost_gendev);
 	pm_runtime_enable(&shost->shost_gendev);
 	device_enable_async_suspend(&shost->shost_gendev);
@@ -290,6 +296,7 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 		goto out_destroy_host;
 
 	scsi_proc_host_add(shost);
+	scsi_autopm_put_host(shost);
 	return error;
 
  out_destroy_host:

drivers/scsi/scsi_pm.c

@@ -139,6 +139,16 @@ static int scsi_bus_resume_common(struct device *dev,
 	else
 		fn = NULL;
 
+	/*
+	 * Forcibly set runtime PM status of request queue to "active" to
+	 * make sure we can again get requests from the queue (see also
+	 * blk_pm_peek_request()).
+	 *
+	 * The resume hook will correct runtime PM status of the disk.
+	 */
+	if (scsi_is_sdev_device(dev) && pm_runtime_suspended(dev))
+		blk_set_runtime_active(to_scsi_device(dev)->request_queue);
+
 	if (fn) {
 		async_schedule_domain(fn, dev, &scsi_sd_pm_domain);
 

include/linux/blkdev.h

@@ -1029,6 +1029,7 @@ extern int blk_pre_runtime_suspend(struct request_queue *q);
 extern void blk_post_runtime_suspend(struct request_queue *q, int err);
 extern void blk_pre_runtime_resume(struct request_queue *q);
 extern void blk_post_runtime_resume(struct request_queue *q, int err);
+extern void blk_set_runtime_active(struct request_queue *q);
 #else
 static inline void blk_pm_runtime_init(struct request_queue *q,
 	struct device *dev) {}
@@ -1039,6 +1040,7 @@ static inline int blk_pre_runtime_suspend(struct request_queue *q)
 static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
 static inline void blk_pre_runtime_resume(struct request_queue *q) {}
 static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
+extern inline void blk_set_runtime_active(struct request_queue *q) {}
 #endif
 
 /*