1 files changed, 121 insertions, 24 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 3c2d228..c0908c2 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -247,7 +247,7 @@ u8 ata_sff_check_status(struct ata_port *ap)
  *	LOCKING:
  *	Inherited from caller.
  */
-u8 ata_sff_altstatus(struct ata_port *ap)
+static u8 ata_sff_altstatus(struct ata_port *ap)
 {
 	if (ap->ops->sff_check_altstatus)
 		return ap->ops->sff_check_altstatus(ap);
@@ -256,6 +256,93 @@ u8 ata_sff_altstatus(struct ata_port *ap)
 }
 
 /**
+ *	ata_sff_irq_status - Check if the device is busy
+ *	@ap: port where the device is
+ *
+ *	Determine if the port is currently busy. Uses altstatus
+ *	if available in order to avoid clearing shared IRQ status
+ *	when finding an IRQ source. Non ctl capable devices don't
+ *	share interrupt lines fortunately for us.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+static u8 ata_sff_irq_status(struct ata_port *ap)
+{
+	u8 status;
+
+	if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
+		status = ata_sff_altstatus(ap);
+		/* Not us: We are busy */
+		if (status & ATA_BUSY)
+		    	return status;
+	}
+	/* Clear INTRQ latch */
+	status = ap->ops->sff_check_status(ap);
+	return status;
+}
+
+/**
+ *	ata_sff_sync - Flush writes
+ *	@ap: Port to wait for.
+ *
+ *	CAUTION:
+ *	If we have an mmio device with no ctl and no altstatus
+ *	method this will fail. No such devices are known to exist.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+static void ata_sff_sync(struct ata_port *ap)
+{
+	if (ap->ops->sff_check_altstatus)
+		ap->ops->sff_check_altstatus(ap);
+	else if (ap->ioaddr.altstatus_addr)
+		ioread8(ap->ioaddr.altstatus_addr);
+}
+
+/**
+ *	ata_sff_pause		-	Flush writes and wait 400nS
+ *	@ap: Port to pause for.
+ *
+ *	CAUTION:
+ *	If we have an mmio device with no ctl and no altstatus
+ *	method this will fail. No such devices are known to exist.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+void ata_sff_pause(struct ata_port *ap)
+{
+	ata_sff_sync(ap);
+	ndelay(400);
+}
+
+/**
+ *	ata_sff_dma_pause	-	Pause before commencing DMA
+ *	@ap: Port to pause for.
+ *
+ *	Perform I/O fencing and ensure sufficient cycle delays occur
+ *	for the HDMA1:0 transition
+ */
+ 
+void ata_sff_dma_pause(struct ata_port *ap)
+{
+	if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
+		/* An altstatus read will cause the needed delay without
+		   messing up the IRQ status */
+		ata_sff_altstatus(ap);
+		return;
+	}
+	/* There are no DMA controllers without ctl. BUG here to ensure
+	   we never violate the HDMA1:0 transition timing and risk
+	   corruption. */
+	BUG();
+}
+
+/**
  *	ata_sff_busy_sleep - sleep until BSY clears, or timeout
  *	@ap: port containing status register to be polled
  *	@tmout_pat: impatience timeout
@@ -742,7 +829,7 @@ static void ata_pio_sectors(struct ata_queued_cmd *qc)
 	} else
 		ata_pio_sector(qc);
 
-	ata_sff_altstatus(qc->ap); /* flush */
+	ata_sff_sync(qc->ap); /* flush */
 }
 
 /**
@@ -763,8 +850,9 @@ static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
 	WARN_ON(qc->dev->cdb_len < 12);
 
 	ap->ops->sff_data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
-	ata_sff_altstatus(ap); /* flush */
-
+	ata_sff_sync(ap);
+	/* FIXME: If the CDB is for DMA do we need to do the transition delay
+	   or is bmdma_start guaranteed to do it ? */
 	switch (qc->tf.protocol) {
 	case ATAPI_PROT_PIO:
 		ap->hsm_task_state = HSM_ST;
@@ -905,7 +993,7 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc)
 
 	if (unlikely(__atapi_pio_bytes(qc, bytes)))
 		goto err_out;
-	ata_sff_altstatus(ap); /* flush */
+	ata_sff_sync(ap); /* flush */
 
 	return;
 
@@ -1006,6 +1094,7 @@ static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
 int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
 		     u8 status, int in_wq)
 {
+	struct ata_eh_info *ehi = &ap->link.eh_info;
 	unsigned long flags = 0;
 	int poll_next;
 
@@ -1037,9 +1126,12 @@ fsm_start:
 			if (likely(status & (ATA_ERR | ATA_DF)))
 				/* device stops HSM for abort/error */
 				qc->err_mask |= AC_ERR_DEV;
-			else
+			else {
 				/* HSM violation. Let EH handle this */
+				ata_ehi_push_desc(ehi,
+					"ST_FIRST: !(DRQ|ERR|DF)");
 				qc->err_mask |= AC_ERR_HSM;
+			}
 
 			ap->hsm_task_state = HSM_ST_ERR;
 			goto fsm_start;
@@ -1058,9 +1150,9 @@ fsm_start:
 			 * the CDB.
 			 */
 			if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
-				ata_port_printk(ap, KERN_WARNING,
-						"DRQ=1 with device error, "
-						"dev_stat 0x%X\n", status);
+				ata_ehi_push_desc(ehi, "ST_FIRST: "
+					"DRQ=1 with device error, "
+					"dev_stat 0x%X", status);
 				qc->err_mask |= AC_ERR_HSM;
 				ap->hsm_task_state = HSM_ST_ERR;
 				goto fsm_start;
@@ -1117,9 +1209,9 @@ fsm_start:
 			 * let the EH abort the command or reset the device.
 			 */
 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
-				ata_port_printk(ap, KERN_WARNING, "DRQ=1 with "
-						"device error, dev_stat 0x%X\n",
-						status);
+				ata_ehi_push_desc(ehi, "ST-ATAPI: "
+					"DRQ=1 with device error, "
+					"dev_stat 0x%X", status);
 				qc->err_mask |= AC_ERR_HSM;
 				ap->hsm_task_state = HSM_ST_ERR;
 				goto fsm_start;
@@ -1138,13 +1230,17 @@ fsm_start:
 				if (likely(status & (ATA_ERR | ATA_DF)))
 					/* device stops HSM for abort/error */
 					qc->err_mask |= AC_ERR_DEV;
-				else
+				else {
 					/* HSM violation. Let EH handle this.
 					 * Phantom devices also trigger this
 					 * condition.  Mark hint.
 					 */
+					ata_ehi_push_desc(ehi, "ST-ATA: "
+						"DRQ=1 with device error, "
+						"dev_stat 0x%X", status);
 					qc->err_mask |= AC_ERR_HSM |
 							AC_ERR_NODEV_HINT;
+				}
 
 				ap->hsm_task_state = HSM_ST_ERR;
 				goto fsm_start;
@@ -1169,8 +1265,12 @@ fsm_start:
 					status = ata_wait_idle(ap);
 				}
 
-				if (status & (ATA_BUSY | ATA_DRQ))
+				if (status & (ATA_BUSY | ATA_DRQ)) {
+					ata_ehi_push_desc(ehi, "ST-ATA: "
+						"BUSY|DRQ persists on ERR|DF, "
+						"dev_stat 0x%X", status);
 					qc->err_mask |= AC_ERR_HSM;
+				}
 
 				/* ata_pio_sectors() might change the
 				 * state to HSM_ST_LAST. so, the state
@@ -1489,14 +1589,10 @@ inline unsigned int ata_sff_host_intr(struct ata_port *ap,
 		goto idle_irq;
 	}
 
-	/* check altstatus */
-	status = ata_sff_altstatus(ap);
-	if (status & ATA_BUSY)
-		goto idle_irq;
 
-	/* check main status, clearing INTRQ */
-	status = ap->ops->sff_check_status(ap);
-	if (unlikely(status & ATA_BUSY))
+	/* check main status, clearing INTRQ if needed */
+	status = ata_sff_irq_status(ap);
+	if (status & ATA_BUSY)
 		goto idle_irq;
 
 	/* ack bmdma irq events */
@@ -2030,7 +2126,7 @@ void ata_sff_error_handler(struct ata_port *ap)
 		ap->ops->bmdma_stop(qc);
 	}
 
-	ata_sff_altstatus(ap);
+	ata_sff_sync(ap);		/* FIXME: We don't need this */
 	ap->ops->sff_check_status(ap);
 	ap->ops->sff_irq_clear(ap);
 
@@ -2203,7 +2299,7 @@ void ata_bmdma_stop(struct ata_queued_cmd *qc)
 		 mmio + ATA_DMA_CMD);
 
 	/* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
-	ata_sff_altstatus(ap);        /* dummy read */
+	ata_sff_dma_pause(ap);
 }
 
 /**
@@ -2722,7 +2818,8 @@ EXPORT_SYMBOL_GPL(ata_sff_qc_prep);
 EXPORT_SYMBOL_GPL(ata_sff_dumb_qc_prep);
 EXPORT_SYMBOL_GPL(ata_sff_dev_select);
 EXPORT_SYMBOL_GPL(ata_sff_check_status);
-EXPORT_SYMBOL_GPL(ata_sff_altstatus);
+EXPORT_SYMBOL_GPL(ata_sff_dma_pause);
+EXPORT_SYMBOL_GPL(ata_sff_pause);
 EXPORT_SYMBOL_GPL(ata_sff_busy_sleep);
 EXPORT_SYMBOL_GPL(ata_sff_wait_ready);
 EXPORT_SYMBOL_GPL(ata_sff_tf_load);