implement PM support

index bbfd176..c25d8d2 100644
@@ -139,7 +139,9 @@ enum {
 	ATA_DEV_ATA_UNSUP	= 2,	/* ATA device (unsupported) */
 	ATA_DEV_ATAPI		= 3,	/* ATAPI device */
 	ATA_DEV_ATAPI_UNSUP	= 4,	/* ATAPI device (unsupported) */
-	ATA_DEV_NONE		= 5,	/* no device */
+	ATA_DEV_PM		= 5,	/* SATA port multiplier */
+	ATA_DEV_PM_UNSUP	= 6,	/* SATA port multiplier (unsupported) */
+	ATA_DEV_NONE		= 7,	/* no device */
 
 	ATA_DEV_ERING_SIZE	= 32,	/* record 32 recent errors */
 

@@ -161,6 +163,8 @@ enum {
 	ATA_FLAG_PIO_POLLING	= (1 << 10), /* use polling PIO if LLD
 					      * doesn't handle PIO interrupts */
 	ATA_FLAG_NCQ		= (1 << 11), /* host supports NCQ */
+	ATA_FLAG_PM		= (1 << 12), /* host supports port multiplier */
+	ATA_FLAG_SDB_NOTIFY	= (1 << 13), /* host support SDB notify */
 
 	ATA_FLAG_DEBUGMSG	= (1 << 14),
 	ATA_FLAG_FLUSH_PORT_TASK = (1 << 15), /* flush port task */

@@ -263,6 +267,9 @@ enum {
 	ATA_PROBE_MAX_TRIES	= 3,
 	ATA_EH_RESET_TRIES	= 3,
 	ATA_EH_DEV_TRIES	= 3,
+	ATA_EH_PM_TRIES		= 5,
+	ATA_EH_PM_RESET_TRIES	= 2,
+	ATA_EH_PM_LINK_TRIES	= 2,
 
 	/* timing constants in millisecs */
 	ATA_DEBOUNCE_QUICK_INTERVAL	= 5,

@@ -272,6 +279,8 @@ enum {
 	ATA_DEBOUNCE_INTERVAL	= 10,
 	ATA_DEBOUNCE_DURATION	= 500,
 	ATA_DEBOUNCE_TIMEOUT	= 10000,
+
+	ATA_PM_SCR_TIMEOUT	= 500,
 };
 
 enum hsm_task_states {

@@ -433,7 +442,12 @@ struct ata_device {
 	/* fields above n_sectors are not cleared across device init */
 	u64			n_sectors;	/* size of device, if ATA */
 	unsigned int		class;		/* ATA_DEV_xxx */
-	u16			id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
+
+	union {
+		u16		id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
+		u32		gscr[ATA_PM_GSCR_DWORDS]; /* PM GSCR block */
+	};
+
 	u8			pio_mode;
 	u8			dma_mode;
 	u8			xfer_mode;

@@ -580,6 +594,12 @@ struct ata_port_operations {
 	void (*qc_prep) (struct ata_queued_cmd *qc);
 	unsigned int (*qc_issue) (struct ata_queued_cmd *qc);
 
+	/* port multiplier */
+	void (*pm_attach) (struct ata_port *ap);
+	void (*pm_detach) (struct ata_port *ap);
+	int (*pm_read) (struct ata_device *dev, int pmp, int reg, u32 *r_val);
+	int (*pm_write) (struct ata_device *dev, int pmp, int reg, u32 val);
+
 	/* Error handlers.  ->error_handler overrides ->eng_timeout and
 	 * indicates that new-style EH is in place.
 	 */

@@ -894,12 +914,14 @@ static inline unsigned int ata_tag_inter
  */
 static inline unsigned int ata_class_enabled(unsigned int class)
 {
-	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI;
+	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI ||
+		class == ATA_DEV_PM;
 }
 
 static inline unsigned int ata_class_disabled(unsigned int class)
 {
-	return class == ATA_DEV_ATA_UNSUP || class == ATA_DEV_ATAPI_UNSUP;
+	return class == ATA_DEV_ATA_UNSUP || class == ATA_DEV_ATAPI_UNSUP ||
+		class == ATA_DEV_PM_UNSUP;
 }
 
 static inline unsigned int ata_class_absent(unsigned int class)

index 148d84d..133a6e6 100644
@@ -5949,6 +5949,14 @@ EXPORT_SYMBOL_GPL(ata_device_resume);
 EXPORT_SYMBOL_GPL(ata_scsi_device_suspend);
 EXPORT_SYMBOL_GPL(ata_scsi_device_resume);
 
+EXPORT_SYMBOL_GPL(ata_pm_read_init_tf);
+EXPORT_SYMBOL_GPL(ata_pm_read_val);
+EXPORT_SYMBOL_GPL(ata_pm_write_init_tf);
+EXPORT_SYMBOL_GPL(ata_pm_std_prereset);
+EXPORT_SYMBOL_GPL(ata_pm_std_hardreset);
+EXPORT_SYMBOL_GPL(ata_pm_std_postreset);
+EXPORT_SYMBOL_GPL(ata_pm_do_eh);
+
 EXPORT_SYMBOL_GPL(ata_eng_timeout);
 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
 EXPORT_SYMBOL_GPL(ata_link_abort);

994 lines not on this page · raw message

index 0f3cefe..7210c87 100644
@@ -110,6 +110,12 @@ extern void ata_scsi_rbuf_fill(struct at
                                            u8 *rbuf, unsigned int buflen));
 extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
 
+/* libata-pm.c */
+extern int ata_pm_scr_read(struct ata_link *link, int reg, u32 *val);
+extern int ata_pm_scr_write(struct ata_link *link, int reg, u32 val);
+extern int ata_pm_attach(struct ata_device *dev);
+extern void ata_pm_detach(struct ata_device *dev);
+
 /* libata-eh.c */
 extern void ata_ering_init(struct ata_ering *ering, int size);
 extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);

index c25d8d2..5772797 100644
@@ -809,6 +809,24 @@ extern unsigned long ata_pci_default_fil
 #endif /* CONFIG_PCI */
 
 /*
+ * PM
+ */
+extern void ata_pm_read_init_tf(struct ata_taskfile *tf,
+				struct ata_device *dev, int pmp, int reg);
+extern u32 ata_pm_read_val(const struct ata_taskfile *tf);
+extern void ata_pm_write_init_tf(struct ata_taskfile *tf,
+				 struct ata_device *dev,
+				 int pmp, int reg, u32 val);
+extern int ata_pm_std_prereset(struct ata_link *link);
+extern int ata_pm_std_hardreset(struct ata_link *link, unsigned int *class);
+extern void ata_pm_std_postreset(struct ata_link *link, unsigned int *class);
+extern void ata_pm_do_eh(struct ata_port *ap,
+		ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
+		ata_reset_fn_t hardreset, ata_postreset_fn_t postreset,
+		ata_prereset_fn_t pm_prereset, ata_reset_fn_t pm_softreset,
+		ata_reset_fn_t pm_hardreset, ata_postreset_fn_t pm_postreset);
+
+/*
  * EH
  */
 extern void ata_eng_timeout(struct ata_port *ap);

index e3d13d6..e38e1fc 100644
@@ -138,7 +138,7 @@ enum {
 	PORT_CS_INIT		= (1 << 2), /* port initialize */
 	PORT_CS_IRQ_WOC		= (1 << 3), /* interrupt write one to clear */
 	PORT_CS_CDB16		= (1 << 5), /* 0=12b cdb, 1=16b cdb */
-	PORT_CS_RESUME		= (1 << 6), /* port resume */
+	PORT_CS_PM_RESUME	= (1 << 6), /* PM resume */
 	PORT_CS_32BIT_ACTV	= (1 << 10), /* 32-bit activation */
 	PORT_CS_PM_EN		= (1 << 13), /* port multiplier enable */
 	PORT_CS_RDY		= (1 << 31), /* port ready to accept commands */

@@ -1128,7 +1128,7 @@ static int sil24_init_one(struct pci_dev
 		writel(PORT_CS_32BIT_ACTV, port + PORT_CTRL_CLR);
 
 		/* Clear port multiplier enable and resume bits */
-		writel(PORT_CS_PM_EN | PORT_CS_RESUME, port + PORT_CTRL_CLR);
+		writel(PORT_CS_PM_EN | PORT_CS_PM_RESUME, port + PORT_CTRL_CLR);
 	}
 
 	/* Turn on interrupts */

index e38e1fc..dfbe750 100644
@@ -103,6 +103,10 @@ enum {
 	PORT_LRAM_SLOT_SZ	= 0x0080, /* 32 bytes PRB + 2 SGE, ACT... */
 
 	PORT_PM			= 0x0f80, /* 8 bytes PM * 16 (128 bytes) */
+	PORT_PM_STATUS		= 0x0000, /* port device status offset */
+	PORT_PM_QACTIVE		= 0x0004, /* port device QActive offset */
+	PORT_PM_SIZE		= 0x0008, /* 8 bytes per PM */
+
 		/* 32 bit regs */
 	PORT_CTRL_STAT		= 0x1000, /* write: ctrl-set, read: stat */
 	PORT_CTRL_CLR		= 0x1004, /* write: ctrl-clear */

@@ -125,6 +129,7 @@ enum {
 	PORT_PHY_CFG		= 0x1050,
 	PORT_SLOT_STAT		= 0x1800,
 	PORT_CMD_ACTIVATE	= 0x1c00, /* 64 bit cmd activate * 31 (248 bytes) */
+	PORT_CONTEXT		= 0x1e04,
 	PORT_EXEC_DIAG		= 0x1e00, /* 32bit exec diag * 16 (64 bytes, 0-10 used on 3124) */
 	PORT_PSD_DIAG		= 0x1e40, /* 32bit psd diag * 16 (64 bytes, 0-8 used on 3124) */
 	PORT_SCONTROL		= 0x1f00,

index dfbe750..34f2e67 100644
@@ -515,16 +515,59 @@ static int sil24_init_port(struct ata_po
 	return 0;
 }
 
-static int sil24_softreset(struct ata_link *link, unsigned int *class)
+static int sil24_exec_polled_cmd(struct ata_port *ap, u32 ctrl,
+				 const struct ata_taskfile *tf,
+				 int pmp, int is_cmd,
+				 unsigned long timeout_msec)
 {
-	struct ata_port *ap = link->ap;
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
 	struct sil24_port_priv *pp = ap->private_data;
 	struct sil24_prb *prb = &pp->cmd_block[0].ata.prb;
 	dma_addr_t paddr = pp->cmd_block_dma;
+	u32 irq_enabled, irq_mask, irq_stat;
+	int rc;
+
+	prb->ctrl = cpu_to_le16(ctrl);
+	ata_tf_to_fis(tf, pmp, is_cmd, prb->fis);
+
+	/* temporarily plug completion and error interrupts */
+	irq_enabled = readl(port + PORT_IRQ_ENABLE_SET);
+	writel(PORT_IRQ_COMPLETE | PORT_IRQ_ERROR, port + PORT_IRQ_ENABLE_CLR);
+
+	writel((u32)paddr, port + PORT_CMD_ACTIVATE);
+	writel((u64)paddr >> 32, port + PORT_CMD_ACTIVATE + 4);
+
+	irq_mask = (PORT_IRQ_COMPLETE | PORT_IRQ_ERROR) << PORT_IRQ_RAW_SHIFT;
+	irq_stat = ata_wait_register(port + PORT_IRQ_STAT, irq_mask, 0x0,
+				     10, timeout_msec);
+
+	writel(irq_mask, port + PORT_IRQ_STAT); /* clear IRQs */
+	irq_stat >>= PORT_IRQ_RAW_SHIFT;
+
+	if (irq_stat & PORT_IRQ_COMPLETE)
+		rc = 0;
+	else {
+		/* force port into known state */
+		sil24_init_port(ap);
+
+		if (irq_stat & PORT_IRQ_ERROR)
+			rc = -EIO;
+		else
+			rc = -EBUSY;
+	}
+
+	/* restore IRQ enabled */
+	writel(irq_enabled, port + PORT_IRQ_ENABLE_SET);
+
+	return rc;
+}
+
+static int sil24_softreset(struct ata_link *link, unsigned int *class)
+{
+	struct ata_port *ap = link->ap;
 	struct ata_taskfile tf;
-	u32 mask, irq_stat;
 	const char *reason;
+	int rc;
 
 	DPRINTK("ENTER\n");
 

@@ -541,24 +584,14 @@ static int sil24_softreset(struct ata_li
 	}
 
 	/* do SRST */
-	prb->ctrl = cpu_to_le16(PRB_CTRL_SRST);
-	prb->fis[1] = 0; /* no PM yet */
-
-	writel((u32)paddr, port + PORT_CMD_ACTIVATE);
-	writel((u64)paddr >> 32, port + PORT_CMD_ACTIVATE + 4);
-
-	mask = (PORT_IRQ_COMPLETE | PORT_IRQ_ERROR) << PORT_IRQ_RAW_SHIFT;
-	irq_stat = ata_wait_register(port + PORT_IRQ_STAT, mask, 0x0,
-				     100, ATA_TMOUT_BOOT / HZ * 1000);
-
-	writel(irq_stat, port + PORT_IRQ_STAT); /* clear IRQs */
-	irq_stat >>= PORT_IRQ_RAW_SHIFT;
-
-	if (!(irq_stat & PORT_IRQ_COMPLETE)) {
-		if (irq_stat & PORT_IRQ_ERROR)
-			reason = "SRST command error";
-		else
-			reason = "timeout";
+	ata_tf_init(link->device, &tf);	/* doesn't really matter */
+	rc = sil24_exec_polled_cmd(ap, PRB_CTRL_SRST, &tf, 0, 0,
+				   ATA_TMOUT_BOOT / HZ * 1000);
+	if (rc == -EBUSY) {
+		reason = "timeout";
+		goto err;
+	} else if (rc) {
+		reason = "SRST command error";
 		goto err;
 	}
 

index 34f2e67..75b04e2 100644
@@ -562,7 +562,8 @@ static int sil24_exec_polled_cmd(struct 
 	return rc;
 }
 
-static int sil24_softreset(struct ata_link *link, unsigned int *class)
+static int sil24_do_softreset(struct ata_link *link, unsigned int *class,
+			      int pmp)
 {
 	struct ata_port *ap = link->ap;
 	struct ata_taskfile tf;

@@ -585,7 +586,7 @@ static int sil24_softreset(struct ata_li
 
 	/* do SRST */
 	ata_tf_init(link->device, &tf);	/* doesn't really matter */
-	rc = sil24_exec_polled_cmd(ap, PRB_CTRL_SRST, &tf, 0, 0,
+	rc = sil24_exec_polled_cmd(ap, PRB_CTRL_SRST, &tf, pmp, 0,
 				   ATA_TMOUT_BOOT / HZ * 1000);
 	if (rc == -EBUSY) {
 		reason = "timeout";

@@ -610,6 +611,11 @@ static int sil24_softreset(struct ata_li
 	return -EIO;
 }
 
+static int sil24_softreset(struct ata_link *link, unsigned int *class)
+{
+	return sil24_do_softreset(link, class, 0);
+}
+
 static int sil24_hardreset(struct ata_link *link, unsigned int *class)
 {
 	struct ata_port *ap = link->ap;

index 75b04e2..1979cfc 100644
@@ -165,7 +165,7 @@ enum {
 
 	DEF_PORT_IRQ		= PORT_IRQ_COMPLETE | PORT_IRQ_ERROR |
 				  PORT_IRQ_PHYRDY_CHG | PORT_IRQ_DEV_XCHG |
-				  PORT_IRQ_UNK_FIS,
+				  PORT_IRQ_UNK_FIS | PORT_IRQ_SDB_NOTIFY,
 
 	/* bits[27:16] are unmasked (raw) */
 	PORT_IRQ_RAW_SHIFT	= 16,

@@ -234,7 +234,8 @@ enum {
 	/* host flags */
 	SIL24_COMMON_FLAGS	= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
 				  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
-				  ATA_FLAG_NCQ,
+				  ATA_FLAG_NCQ | ATA_FLAG_PM |
+				  ATA_FLAG_SDB_NOTIFY,
 	SIL24_FLAG_PCIX_IRQ_WOC	= (1 << 24), /* IRQ loss errata on PCI-X */
 
 	IRQ_STAT_4PORTS		= 0xf,

@@ -328,10 +329,15 @@ struct sil24_host_priv {
 static void sil24_dev_config(struct ata_port *ap, struct ata_device *dev);
 static u32 sil24_scr_read(struct ata_port *ap, unsigned sc_reg);
 static void sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val);
+static int sil24_qc_defer(struct ata_queued_cmd *qc);
 static void sil24_qc_prep(struct ata_queued_cmd *qc);
 static unsigned int sil24_qc_issue(struct ata_queued_cmd *qc);
 static void sil24_irq_clear(struct ata_port *ap);
 static irqreturn_t sil24_interrupt(int irq, void *dev_instance, struct pt_regs *regs);
+static void sil24_pm_attach(struct ata_port *ap);
+static void sil24_pm_detach(struct ata_port *ap);
+static int sil24_pm_read(struct ata_device *dev, int pmp, int reg, u32 *r_val);
+static int sil24_pm_write(struct ata_device *dev, int pmp, int reg, u32 val);
 static void sil24_freeze(struct ata_port *ap);
 static void sil24_thaw(struct ata_port *ap);
 static void sil24_error_handler(struct ata_port *ap);

@@ -385,7 +391,7 @@ static const struct ata_port_operations 
 	.check_altstatus	= ata_noop_check_status,
 	.dev_select		= ata_noop_dev_select,
 
-	.qc_defer		= ata_std_qc_defer,
+	.qc_defer		= sil24_qc_defer,
 	.qc_prep		= sil24_qc_prep,
 	.qc_issue		= sil24_qc_issue,
 

@@ -395,6 +401,11 @@ static const struct ata_port_operations 
 	.scr_read		= sil24_scr_read,
 	.scr_write		= sil24_scr_write,
 
+	.pm_attach		= sil24_pm_attach,
+	.pm_detach		= sil24_pm_detach,
+	.pm_read		= sil24_pm_read,
+	.pm_write		= sil24_pm_write,
+
 	.freeze			= sil24_freeze,
 	.thaw			= sil24_thaw,
 	.error_handler		= sil24_error_handler,

@@ -499,6 +510,31 @@ static void sil24_scr_write(struct ata_p
 	}
 }
 
+static void sil24_config_pm(struct ata_port *ap, int attached)
+{
+	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
+
+	if (attached)
+		writel(PORT_CS_PM_EN, port + PORT_CTRL_STAT);
+	else
+		writel(PORT_CS_PM_EN, port + PORT_CTRL_CLR);
+}
+
+static void sil24_clear_pm(struct ata_port *ap)
+{
+	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
+	int i;
+
+	writel(PORT_CS_PM_RESUME, port + PORT_CTRL_CLR);
+
+	for (i = 0; i < ATA_PM_MAX_PORTS; i++) {
+		void __iomem *pm_base = port + PORT_PM + i * PORT_PM_SIZE;
+
+		writel(0, pm_base + PORT_PM_STATUS);
+		writel(0, pm_base + PORT_PM_QACTIVE);
+	}
+}
+
 static int sil24_init_port(struct ata_port *ap)
 {
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;

@@ -510,6 +546,9 @@ static int sil24_init_port(struct ata_po
 	tmp = ata_wait_register(port + PORT_CTRL_STAT,
 				PORT_CS_RDY, 0, 10, 100);
 
+	/* clear PM error status */
+	sil24_clear_pm(ap);
+
 	if ((tmp & (PORT_CS_INIT | PORT_CS_RDY)) != PORT_CS_RDY)
 		return -EIO;
 	return 0;

@@ -613,7 +652,7 @@ static int sil24_do_softreset(struct ata
 
 static int sil24_softreset(struct ata_link *link, unsigned int *class)
 {
-	return sil24_do_softreset(link, class, 0);
+	return sil24_do_softreset(link, class, ATA_PM_CTRL_PORT);
 }
 
 static int sil24_hardreset(struct ata_link *link, unsigned int *class)

@@ -684,6 +723,38 @@ static inline void sil24_fill_sg(struct 
 	}
 }
 
+static int sil24_qc_defer(struct ata_queued_cmd *qc)
+{
+	struct ata_link *link = qc->dev->link;
+	struct ata_port *ap = link->ap;
+	u8 prot = qc->tf.protocol;
+	int is_atapi = (prot == ATA_PROT_ATAPI ||
+			prot == ATA_PROT_ATAPI_NODATA ||
+			prot == ATA_PROT_ATAPI_DMA);
+
+	/* ATAPI commands completing with CHECK_SENSE cause various
+	 * weird problems if other commands are active.  PM DMA CS
+	 * errata doesn't cover all and HSM violation occurs even with
+	 * only one other device active.  Always run an ATAPI command
+	 * by itself.
+	 */
+	if (unlikely(ap->excl_link)) {
+		if (link == ap->excl_link) {
+			if (ap->nr_active_links)
+				return ATA_DEFER_PORT;
+			qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
+		} else
+			return ATA_DEFER_LINK;
+	} else if (unlikely(is_atapi)) {
+		ap->excl_link = link;
+		if (ap->nr_active_links)
+			return ATA_DEFER_PORT;
+		qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
+	}
+
+	return ata_std_qc_defer(qc);
+}
+
 static void sil24_qc_prep(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;

@@ -756,6 +827,63 @@ static void sil24_irq_clear(struct ata_p
 	/* unused */
 }
 
+static void sil24_pm_attach(struct ata_port *ap)
+{
+	sil24_config_pm(ap, 1);
+	sil24_clear_pm(ap);
+}
+
+static void sil24_pm_detach(struct ata_port *ap)
+{
+	sil24_clear_pm(ap);
+	sil24_config_pm(ap, 0);
+}
+
+static int sil24_pm_read(struct ata_device *dev, int pmp, int reg, u32 *r_val)
+{
+	struct ata_port *ap = dev->link->ap;
+	struct ata_taskfile tf;
+	int rc;
+
+	ata_pm_read_init_tf(&tf, dev, pmp, reg);
+	rc = sil24_exec_polled_cmd(ap, 0, &tf, ATA_PM_CTRL_PORT, 1,
+				   ATA_PM_SCR_TIMEOUT);
+	if (rc == 0) {
+		sil24_read_tf(ap, 0, &tf);
+		*r_val = ata_pm_read_val(&tf);
+	}
+	return rc;
+}
+
+static int sil24_pm_write(struct ata_device *dev, int pmp, int reg, u32 val)
+{
+	struct ata_port *ap = dev->link->ap;
+	struct ata_taskfile tf;
+
+	ata_pm_write_init_tf(&tf, dev, pmp, reg, val);
+	return sil24_exec_polled_cmd(ap, 0, &tf, ATA_PM_CTRL_PORT, 1,
+				     ATA_PM_SCR_TIMEOUT);
+}
+
+static int sil24_pm_softreset(struct ata_link *link, unsigned int *class)
+{
+	return sil24_do_softreset(link, class, link->pmp);
+}
+
+static int sil24_pm_hardreset(struct ata_link *link, unsigned int *class)
+{
+	int rc;
+
+	rc = sil24_init_port(link->ap);
+	if (rc) {
+		ata_link_printk(link, KERN_ERR,
+				"hardreset failed (port not ready)\n");
+		return rc;
+	}
+
+	return ata_pm_std_hardreset(link, class);
+}
+
 static void sil24_freeze(struct ata_port *ap)
 {
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;

@@ -782,8 +910,9 @@ static void sil24_thaw(struct ata_port *
 static void sil24_error_intr(struct ata_port *ap)
 {
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
-	struct ata_eh_info *ehi = &ap->link.eh_info;
 	int freeze = 0;
+	struct ata_link *link;
+	struct ata_eh_info *ehi;
 	u32 irq_stat;
 
 	/* on error, we need to clear IRQ explicitly */

@@ -791,6 +920,8 @@ static void sil24_error_intr(struct ata_
 	writel(irq_stat, port + PORT_IRQ_STAT);
 
 	/* first, analyze and record host port events */
+	link = &ap->link;
+	ehi = &link->eh_info;
 	ata_ehi_clear_desc(ehi);
 
 	ata_ehi_push_desc(ehi, "irq_stat 0x%08x", irq_stat);

@@ -817,12 +948,59 @@ static void sil24_error_intr(struct ata_
 		freeze = 1;
 	}
 
+	if (irq_stat & PORT_IRQ_SDB_NOTIFY) {
+		/* No SNotification register.  We don't know which
+		 * ports should be aborted.  Just let them timeout.
+		 */
+		ehi->err_mask |= AC_ERR_OTHER;
+		ata_ehi_push_desc(ehi, ", SDB notify");
+		ata_port_schedule_eh(ap);
+	}
+
 	/* deal with command error */
 	if (irq_stat & PORT_IRQ_ERROR) {
 		struct sil24_cerr_info *ci = NULL;
+		struct ata_queued_cmd *qc = NULL;
 		unsigned int err_mask = 0, action = 0;
-		struct ata_queued_cmd *qc;
-		u32 cerr;
+		u32 context, cerr;
+		int pmp;
+
+		/* DMA Context Switch Failure in Port Multiplier Mode
+		 * errata.  If we have active commands to 3 or more
+		 * devices, any error condition on active devices can
+		 * corrupt DMA context switching.
+		 */
+		if (ap->nr_active_links >= 3) {
+			ehi->err_mask |= AC_ERR_OTHER;
+			ehi->action |= ATA_EH_HARDRESET;
+			ata_ehi_push_desc(ehi, ", PM DMA CS errata");
+			freeze = 1;
+		}
+
+		/* find out the offending link and qc */
+		if (ap->nr_pm_links) {
+			context = readl(port + PORT_CONTEXT);
+			pmp = (context >> 5) & 0xf;
+
+			if (pmp < ap->nr_pm_links) {
+				link = &ap->pm_link[pmp];
+				ehi = &link->eh_info;
+				qc = ata_qc_from_tag(ap, link->active_tag);
+
+				ata_ehi_clear_desc(ehi);
+				ata_ehi_push_desc(ehi, "irq_stat 0x%08x",
+						  irq_stat);
+
+				ata_link_abort(link);
+			} else {
+				err_mask |= AC_ERR_HSM;
+				action |= ATA_EH_HARDRESET;
+				freeze = 1;
+			}
+		} else {
+			qc = ata_qc_from_tag(ap, link->active_tag);
+			ata_link_abort(link);
+		}
 
 		/* analyze CMD_ERR */
 		cerr = readl(port + PORT_CMD_ERR);

@@ -841,7 +1019,6 @@ static void sil24_error_intr(struct ata_
 		}
 
 		/* record error info */
-		qc = ata_qc_from_tag(ap, ap->link.active_tag);
 		if (qc) {
 			sil24_read_tf(ap, sil24_tag(qc->tag), &qc->result_tf);
 			qc->err_mask |= err_mask;

@@ -849,13 +1026,15 @@ static void sil24_error_intr(struct ata_
 			ehi->err_mask |= err_mask;
 
 		ehi->action |= action;
+
+		/* if PM, resume */
+		if (ap->nr_pm_links)
+			writel(PORT_CS_PM_RESUME, port + PORT_CTRL_STAT);
 	}
 
-	/* freeze or abort */
+	/* freeze? */
 	if (freeze)
 		ata_port_freeze(ap);
-	else
-		ata_port_abort(ap);
 }
 
 static void sil24_finish_qc(struct ata_queued_cmd *qc)

@@ -945,8 +1124,9 @@ static void sil24_error_handler(struct a
 	}
 
 	/* perform recovery */
-	ata_do_eh(ap, ata_std_prereset, sil24_softreset, sil24_hardreset,
-		  ata_std_postreset);
+	ata_pm_do_eh(ap, ata_std_prereset, sil24_softreset, sil24_hardreset,
+		     ata_std_postreset, ata_pm_std_prereset, sil24_pm_softreset,
+		     sil24_pm_hardreset, ata_pm_std_postreset);
 }
 
 static void sil24_post_internal_cmd(struct ata_queued_cmd *qc)

index 1979cfc..9b7f46f 100644
@@ -318,6 +318,7 @@ static struct sil24_cerr_info {
 struct sil24_port_priv {
 	union sil24_cmd_block *cmd_block;	/* 32 cmd blocks */
 	dma_addr_t cmd_block_dma;		/* DMA base addr for them */
+	int do_port_rst;
 };
 
 /* ap->host_set->private_data */

@@ -510,6 +511,30 @@ static void sil24_scr_write(struct ata_p
 	}
 }
 
+static void sil24_config_controller(void __iomem *port,
+				    unsigned long host_flags)
+{
+	/* configure IRQ WoC */
+	if (host_flags & SIL24_FLAG_PCIX_IRQ_WOC)
+		writel(PORT_CS_IRQ_WOC, port + PORT_CTRL_STAT);
+	else
+		writel(PORT_CS_IRQ_WOC, port + PORT_CTRL_CLR);
+
+	/* zero error counters. */
+	writel(0x8000, port + PORT_DECODE_ERR_THRESH);
+	writel(0x8000, port + PORT_CRC_ERR_THRESH);
+	writel(0x8000, port + PORT_HSHK_ERR_THRESH);
+	writel(0x0000, port + PORT_DECODE_ERR_CNT);
+	writel(0x0000, port + PORT_CRC_ERR_CNT);
+	writel(0x0000, port + PORT_HSHK_ERR_CNT);
+
+	/* always use 64bit activation */
+	writel(PORT_CS_32BIT_ACTV, port + PORT_CTRL_CLR);
+
+	/* clear port multiplier enable and resume bits */
+	writel(PORT_CS_PM_EN | PORT_CS_PM_RESUME, port + PORT_CTRL_CLR);
+}
+
 static void sil24_config_pm(struct ata_port *ap, int attached)
 {
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;

@@ -538,6 +563,7 @@ static void sil24_clear_pm(struct ata_po
 static int sil24_init_port(struct ata_port *ap)
 {
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
+	struct sil24_port_priv *pp = ap->private_data;
 	u32 tmp;
 
 	writel(PORT_CS_INIT, port + PORT_CTRL_STAT);

@@ -549,8 +575,12 @@ static int sil24_init_port(struct ata_po
 	/* clear PM error status */
 	sil24_clear_pm(ap);
 
-	if ((tmp & (PORT_CS_INIT | PORT_CS_RDY)) != PORT_CS_RDY)
+	if ((tmp & (PORT_CS_INIT | PORT_CS_RDY)) != PORT_CS_RDY) {
+		pp->do_port_rst = 1;
+		ap->link.eh_context.i.action |= ATA_EH_HARDRESET;
 		return -EIO;
+	}
+
 	return 0;
 }
 

@@ -659,10 +689,34 @@ static int sil24_hardreset(struct ata_li
 {
 	struct ata_port *ap = link->ap;
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
+	struct sil24_port_priv *pp = ap->private_data;
+	int did_port_rst = 0;
 	const char *reason;
 	int tout_msec, rc;
 	u32 tmp;
 
+ retry:
+	/* Sometimes, DEV_RST is not enough to recover the controller.
+	 * This happens a lot after PM DMA CS errata.
+	 */
+	if (pp->do_port_rst) {
+		ata_port_printk(ap, KERN_WARNING, "controller in dubious "
+				"state, performing PORT_RST\n");
+
+		writel(PORT_CS_PORT_RST, port + PORT_CTRL_STAT);
+		msleep(10);
+		writel(PORT_CS_PORT_RST, port + PORT_CTRL_CLR);
+		ata_wait_register(port + PORT_CTRL_STAT, PORT_CS_RDY, 0,
+				  10, 5000);
+
+		/* restore port configuration */
+		sil24_config_controller(port, ap->flags);
+		sil24_config_pm(ap, ap->nr_pm_links);
+
+		pp->do_port_rst = 0;
+		did_port_rst = 1;
+	}
+
 	/* sil24 does the right thing(tm) without any protection */
 	ata_set_sata_spd(link);
 

@@ -700,6 +754,11 @@ static int sil24_hardreset(struct ata_li
 	return -EAGAIN;
 
  err:
+	if (!did_port_rst) {
+		pp->do_port_rst = 1;
+		goto retry;
+	}
+
 	ata_link_printk(link, KERN_ERR, "hardreset failed (%s)\n", reason);
 	return -EIO;
 }

@@ -910,6 +969,7 @@ static void sil24_thaw(struct ata_port *
 static void sil24_error_intr(struct ata_port *ap)
 {
 	void __iomem *port = (void __iomem *)ap->ioaddr.cmd_addr;
+	struct sil24_port_priv *pp = ap->private_data;
 	int freeze = 0;
 	struct ata_link *link;
 	struct ata_eh_info *ehi;

@@ -974,6 +1034,7 @@ static void sil24_error_intr(struct ata_
 			ehi->err_mask |= AC_ERR_OTHER;
 			ehi->action |= ATA_EH_HARDRESET;
 			ata_ehi_push_desc(ehi, ", PM DMA CS errata");
+			pp->do_port_rst = 1;
 			freeze = 1;
 		}
 

@@ -1116,17 +1177,17 @@ static irqreturn_t sil24_interrupt(int i
 
 static void sil24_error_handler(struct ata_port *ap)
 {
-	struct ata_eh_context *ehc = &ap->link.eh_context;
+	struct sil24_port_priv *pp = ap->private_data;
 
-	if (sil24_init_port(ap)) {
+	if (sil24_init_port(ap))
 		ata_eh_freeze_port(ap);
-		ehc->i.action |= ATA_EH_HARDRESET;
-	}
 
 	/* perform recovery */
 	ata_pm_do_eh(ap, ata_std_prereset, sil24_softreset, sil24_hardreset,
 		     ata_std_postreset, ata_pm_std_prereset, sil24_pm_softreset,
 		     sil24_pm_hardreset, ata_pm_std_postreset);
+
+	pp->do_port_rst = 0;
 }
 
 static void sil24_post_internal_cmd(struct ata_queued_cmd *qc)

@@ -1137,8 +1198,10 @@ static void sil24_post_internal_cmd(stru
 		qc->err_mask |= AC_ERR_OTHER;
 
 	/* make DMA engine forget about the failed command */
-	if (qc->err_mask)
-		sil24_init_port(ap);
+	if (qc->err_mask) {
+		if (sil24_init_port(ap))
+			ata_eh_freeze_port(ap);
+	}
 }
 
 static inline void sil24_cblk_free(struct sil24_port_priv *pp, struct device *dev)

@@ -1334,25 +1397,8 @@ static int sil24_init_one(struct pci_dev
 				           "failed to clear port RST\n");
 		}
 
-		/* Configure IRQ WoC */
-		if (probe_ent->host_flags & SIL24_FLAG_PCIX_IRQ_WOC)
-			writel(PORT_CS_IRQ_WOC, port + PORT_CTRL_STAT);
-		else
-			writel(PORT_CS_IRQ_WOC, port + PORT_CTRL_CLR);
-
-		/* Zero error counters. */
-		writel(0x8000, port + PORT_DECODE_ERR_THRESH);
-		writel(0x8000, port + PORT_CRC_ERR_THRESH);
-		writel(0x8000, port + PORT_HSHK_ERR_THRESH);
-		writel(0x0000, port + PORT_DECODE_ERR_CNT);
-		writel(0x0000, port + PORT_CRC_ERR_CNT);
-		writel(0x0000, port + PORT_HSHK_ERR_CNT);
-
-		/* Always use 64bit activation */
-		writel(PORT_CS_32BIT_ACTV, port + PORT_CTRL_CLR);
-
-		/* Clear port multiplier enable and resume bits */
-		writel(PORT_CS_PM_EN | PORT_CS_PM_RESUME, port + PORT_CTRL_CLR);
+		/* configure controller */
+		sil24_config_controller(port, probe_ent->host_flags);
 	}
 
 	/* Turn on interrupts */

index d62a529..3ad8c01 100644
@@ -1420,13 +1420,16 @@ static int ata_do_reset(struct ata_link 
 	return 0;
 }
 
-static int ata_eh_followup_srst_needed(int rc, int classify,
+static int ata_eh_followup_srst_needed(struct ata_port *ap,
+				       int rc, int classify,
 				       const unsigned int *classes)
 {
 	if (rc == -EAGAIN)
 		return 1;
 	if (rc != 0)
 		return 0;
+	if (ap->flags & ATA_FLAG_PM)
+		return 1;
 	if (classify && classes[0] == ATA_DEV_UNKNOWN)
 		return 1;
 	return 0;

@@ -1436,10 +1439,11 @@ int ata_eh_reset(struct ata_link *link, 
 		 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
+	struct ata_port *ap = link->ap;
 	struct ata_eh_context *ehc = &link->eh_context;
 	unsigned int *classes = ehc->classes;
 	int tries = link->reset_tries;
-	int verbose = !(link->ap->flags & ATA_FLAG_LOADING);
+	int verbose = !(ap->flags & ATA_FLAG_LOADING);
 	unsigned int action;
 	ata_reset_fn_t reset;
 	int did_followup_srst, rc;

@@ -1493,7 +1497,7 @@ int ata_eh_reset(struct ata_link *link, 
 
 	did_followup_srst = 0;
 	if (reset == hardreset &&
-	    ata_eh_followup_srst_needed(rc, classify, classes)) {
+	    ata_eh_followup_srst_needed(ap, rc, classify, classes)) {
 		/* okay, let's do follow-up softreset */
 		did_followup_srst = 1;
 		reset = softreset;

index 133a6e6..2cea289 100644
@@ -542,29 +542,46 @@ static unsigned int ata_devchk(struct at
  *	None.
  *
  *	RETURNS:
- *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, or %ATA_DEV_UNKNOWN
- *	the event of failure.
+ *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PM or
+ *	%ATA_DEV_UNKNOWN the event of failure.
  */
-
 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
 {
 	/* Apple's open source Darwin code hints that some devices only
 	 * put a proper signature into the LBA mid/high registers,
 	 * So, we only check those.  It's sufficient for uniqueness.
+	 *
+	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
+	 * signatures for ATA and ATAPI devices attached on SerialATA,
+	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
+	 * spec has never mentioned about using different signatures
+	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
+	 * Multiplier specification began to use 0x69/0x96 to identify
+	 * port multpliers.  ATA/ATAPI-7 dropped descriptions about
+	 * 0x3c/0xc3 and 0x69/0x96 shortly and described them as
+	 * reserved for SerialATA.
+	 *
+	 * We follow the current spec and consider that 0x69/0x96
+	 * identifies a port multiplier.  If there is an ATAPI device
+	 * which returns 0x69/0x96 as its signature, we'll have to
+	 * implement 'try PM, then try ATAPI' logic.
 	 */
-
 	if (((tf->lbam == 0) && (tf->lbah == 0)) ||
 	    ((tf->lbam == 0x3c) && (tf->lbah == 0xc3))) {
 		DPRINTK("found ATA device by sig\n");
 		return ATA_DEV_ATA;
 	}
 
-	if (((tf->lbam == 0x14) && (tf->lbah == 0xeb)) ||
-	    ((tf->lbam == 0x69) && (tf->lbah == 0x96))) {
+	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
 		DPRINTK("found ATAPI device by sig\n");
 		return ATA_DEV_ATAPI;
 	}
 
+	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
+		DPRINTK("found PM device by sig\n");
+		return ATA_DEV_PM;
+	}
+
 	DPRINTK("unknown device\n");
 	return ATA_DEV_UNKNOWN;
 }

@@ -4851,24 +4868,29 @@ int ata_scr_valid(struct ata_link *link)
  *	@val: Place to store read value
  *
  *	Read SCR register @reg of @link into *@val.  This function is
- *	guaranteed to succeed if the cable type of the port is SATA
- *	and the port implements ->scr_read.
+ *	guaranteed to succeed if @link is ap->link, the cable type of
+ *	the port is SATA and the port implements ->scr_read.
  *
  *	LOCKING:
- *	None.
+ *	None if @link is ap->link.  Kernel thread context otherwise.
  *
  *	RETURNS:
  *	0 on success, negative errno on failure.
  */
 int ata_scr_read(struct ata_link *link, int reg, u32 *val)
 {
-	struct ata_port *ap = link->ap;
+	if (ata_is_host_link(link)) {
+		struct ata_port *ap = link->ap;
 
-	if (ata_scr_valid(link)) {
-		*val = ap->ops->scr_read(ap, reg);
-		return 0;
+		if (ata_scr_valid(link)) {
+			*val = ap->ops->scr_read(ap, reg);
+			return 0;
+		}
+
+		return -EOPNOTSUPP;
 	}
-	return -EOPNOTSUPP;
+
+	return ata_pm_scr_read(link, reg, val);
 }
 
 /**

@@ -4878,24 +4900,29 @@ int ata_scr_read(struct ata_link *link, 
  *	@val: value to write
  *
  *	Write @val to SCR register @reg of @link.  This function is
- *	guaranteed to succeed if the cable type of the port is SATA
- *	and the port implements ->scr_read.
+ *	guaranteed to succeed if @link is ap->link, the cable type of
+ *	the port is SATA and the port implements ->scr_read.
  *
  *	LOCKING:
- *	None.
+ *	None if @link is ap->link.  Kernel thread context otherwise.
  *
  *	RETURNS:
  *	0 on success, negative errno on failure.
  */
 int ata_scr_write(struct ata_link *link, int reg, u32 val)
 {
-	struct ata_port *ap = link->ap;
+	if (ata_is_host_link(link)) {
+		struct ata_port *ap = link->ap;
 
-	if (ata_scr_valid(link)) {
-		ap->ops->scr_write(ap, reg, val);
-		return 0;
+		if (ata_scr_valid(link)) {
+			ap->ops->scr_write(ap, reg, val);
+			return 0;
+		}
+
+		return -EOPNOTSUPP;
 	}
-	return -EOPNOTSUPP;
+
+	return ata_pm_scr_write(link, reg, val);
 }
 
 /**

@@ -4908,21 +4935,26 @@ int ata_scr_write(struct ata_link *link,
  *	function performs flush after writing to the register.
  *
  *	LOCKING:
- *	None.
+ *	None if @link is ap->link.  Kernel thread context otherwise.
  *
  *	RETURNS:
  *	0 on success, negative errno on failure.
  */
 int ata_scr_write_flush(struct ata_link *link, int reg, u32 val)
 {
-	struct ata_port *ap = link->ap;
+	if (ata_is_host_link(link)) {
+		struct ata_port *ap = link->ap;
 
-	if (ata_scr_valid(link)) {
-		ap->ops->scr_write(ap, reg, val);
-		ap->ops->scr_read(ap, reg);
-		return 0;
+		if (ata_scr_valid(link)) {
+			ap->ops->scr_write(ap, reg, val);
+			ap->ops->scr_read(ap, reg);
+			return 0;
+		}
+
+		return -EOPNOTSUPP;
 	}
-	return -EOPNOTSUPP;
+
+	return ata_pm_scr_write(link, reg, val);
 }
 
 /**

@@ -5637,6 +5669,8 @@ int ata_scsi_release(struct Scsi_Host *h
 	ap->ops->port_disable(ap);
 	ata_host_remove(ap, 0);
 
+	kfree(ap->pm_link);
+
 	DPRINTK("EXIT\n");
 	return 1;
 }

index 3ad8c01..0fd35ed 100644
@@ -1569,6 +1569,8 @@ static int ata_eh_revalidate_and_attach(
 	ata_link_for_each_dev(dev, link) {
 		if (ehc->i.action & ATA_EH_REVALIDATE && ata_dev_enabled(dev) &&
 		    (!ehc->i.dev || ehc->i.dev == dev)) {
+			WARN_ON(dev->class == ATA_DEV_PM);
+
 			if (ata_link_offline(dev->link)) {
 				rc = -EIO;
 				break;

@@ -1586,6 +1588,13 @@ static int ata_eh_revalidate_and_attach(
 			   ata_class_enabled(ehc->classes[dev->devno])) {
 			dev->class = ehc->classes[dev->devno];
 
+			if (dev->class == ATA_DEV_PM) {
+				rc = ata_pm_attach(dev);
+				if (rc)
+					dev->class = ATA_DEV_UNKNOWN;
+				break;
+			}
+
 			rc = ata_dev_read_id(dev, &dev->class, 1, dev->id);
 			if (rc == 0)
 				rc = ata_dev_configure(dev, 1);

@@ -1760,6 +1769,12 @@ int ata_eh_recover(struct ata_port *ap, 
 		if (rc)
 			goto dev_fail;
 
+		/* if PM got attached, return, we don't know what to do */
+		if (link->device->class == ATA_DEV_PM) {
+			ehc->i.action = 0;
+			return 0;
+		}
+
 		/* configure transfer mode if the port has been reset */
 		if (ehc->flags & ATA_EHC_DID_RESET) {
 			rc = ata_set_mode(link, &dev);