1 files changed, 68 insertions, 14 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 730ef3c384ca..e3877b6843c9 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -33,6 +33,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/gfp.h>
 #include <linux/pci.h>
 #include <linux/libata.h>
 #include <linux/highmem.h>
@@ -1667,6 +1668,7 @@ unsigned int ata_sff_host_intr(struct ata_port *ap,
 {
 	struct ata_eh_info *ehi = &ap->link.eh_info;
 	u8 status, host_stat = 0;
+	bool bmdma_stopped = false;
 
 	VPRINTK("ata%u: protocol %d task_state %d\n",
 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
@@ -1699,6 +1701,7 @@ unsigned int ata_sff_host_intr(struct ata_port *ap,
 
 			/* before we do anything else, clear DMA-Start bit */
 			ap->ops->bmdma_stop(qc);
+			bmdma_stopped = true;
 
 			if (unlikely(host_stat & ATA_DMA_ERR)) {
 				/* error when transfering data to/from memory */
@@ -1716,8 +1719,14 @@ unsigned int ata_sff_host_intr(struct ata_port *ap,
 
 	/* check main status, clearing INTRQ if needed */
 	status = ata_sff_irq_status(ap);
-	if (status & ATA_BUSY)
-		goto idle_irq;
+	if (status & ATA_BUSY) {
+		if (bmdma_stopped) {
+			/* BMDMA engine is already stopped, we're screwed */
+			qc->err_mask |= AC_ERR_HSM;
+			ap->hsm_task_state = HSM_ST_ERR;
+		} else
+			goto idle_irq;
+	}
 
 	/* ack bmdma irq events */
 	ap->ops->sff_irq_clear(ap);
@@ -1762,25 +1771,68 @@ EXPORT_SYMBOL_GPL(ata_sff_host_intr);
 irqreturn_t ata_sff_interrupt(int irq, void *dev_instance)
 {
 	struct ata_host *host = dev_instance;
+	bool retried = false;
 	unsigned int i;
-	unsigned int handled = 0;
+	unsigned int handled, idle, polling;
 	unsigned long flags;
 
 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
 	spin_lock_irqsave(&host->lock, flags);
 
+retry:
+	handled = idle = polling = 0;
 	for (i = 0; i < host->n_ports; i++) {
-		struct ata_port *ap;
+		struct ata_port *ap = host->ports[i];
+		struct ata_queued_cmd *qc;
 
-		ap = host->ports[i];
-		if (ap &&
-		    !(ap->flags & ATA_FLAG_DISABLED)) {
-			struct ata_queued_cmd *qc;
+		if (unlikely(ap->flags & ATA_FLAG_DISABLED))
+			continue;
 
-			qc = ata_qc_from_tag(ap, ap->link.active_tag);
-			if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
-			    (qc->flags & ATA_QCFLAG_ACTIVE))
+		qc = ata_qc_from_tag(ap, ap->link.active_tag);
+		if (qc) {
+			if (!(qc->tf.flags & ATA_TFLAG_POLLING))
 				handled |= ata_sff_host_intr(ap, qc);
+			else
+				polling |= 1 << i;
+		} else
+			idle |= 1 << i;
+	}
+
+	/*
+	 * If no port was expecting IRQ but the controller is actually
+	 * asserting IRQ line, nobody cared will ensue.  Check IRQ
+	 * pending status if available and clear spurious IRQ.
+	 */
+	if (!handled && !retried) {
+		bool retry = false;
+
+		for (i = 0; i < host->n_ports; i++) {
+			struct ata_port *ap = host->ports[i];
+
+			if (polling & (1 << i))
+				continue;
+
+			if (!ap->ops->sff_irq_check ||
+			    !ap->ops->sff_irq_check(ap))
+				continue;
+
+			if (idle & (1 << i)) {
+				ap->ops->sff_check_status(ap);
+				ap->ops->sff_irq_clear(ap);
+			} else {
+				/* clear INTRQ and check if BUSY cleared */
+				if (!(ap->ops->sff_check_status(ap) & ATA_BUSY))
+					retry |= true;
+				/*
+				 * With command in flight, we can't do
+				 * sff_irq_clear() w/o racing with completion.
+				 */
+			}
+		}
+
+		if (retry) {
+			retried = true;
+			goto retry;
 		}
 	}
 
@@ -2261,7 +2313,7 @@ EXPORT_SYMBOL_GPL(ata_sff_postreset);
  *	@qc: command
  *
  *	Drain the FIFO and device of any stuck data following a command
- *	failing to complete. In some cases this is neccessary before a
+ *	failing to complete. In some cases this is necessary before a
  *	reset will recover the device.
  *
  */
@@ -3011,6 +3063,7 @@ EXPORT_SYMBOL_GPL(ata_pci_sff_activate_host);
  *	@ppi: array of port_info, must be enough for two ports
  *	@sht: scsi_host_template to use when registering the host
  *	@host_priv: host private_data
+ *	@hflag: host flags
  *
  *	This is a helper function which can be called from a driver's
  *	xxx_init_one() probe function if the hardware uses traditional
@@ -3031,8 +3084,8 @@ EXPORT_SYMBOL_GPL(ata_pci_sff_activate_host);
  *	Zero on success, negative on errno-based value on error.
  */
 int ata_pci_sff_init_one(struct pci_dev *pdev,
-			 const struct ata_port_info * const *ppi,
-			 struct scsi_host_template *sht, void *host_priv)
+		 const struct ata_port_info * const *ppi,
+		 struct scsi_host_template *sht, void *host_priv, int hflag)
 {
 	struct device *dev = &pdev->dev;
 	const struct ata_port_info *pi = NULL;
@@ -3067,6 +3120,7 @@ int ata_pci_sff_init_one(struct pci_dev *pdev,
 	if (rc)
 		goto out;
 	host->private_data = host_priv;
+	host->flags |= hflag;
 
 	pci_set_master(pdev);
 	rc = ata_pci_sff_activate_host(host, ata_sff_interrupt, sht);