1 files changed, 26 insertions, 30 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 86918634a4c..f2d8a020ea5 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -33,10 +33,6 @@
  *
  * --> ATAPI support (Marvell claims the 60xx/70xx chips can do it).
  *
- * --> Investigate problems with PCI Message Signalled Interrupts (MSI).
- *
- * --> Cache frequently-accessed registers in mv_port_priv to reduce overhead.
- *
  * --> Develop a low-power-consumption strategy, and implement it.
  *
  * --> [Experiment, low priority] Investigate interrupt coalescing.
@@ -72,7 +68,7 @@
 #include <linux/libata.h>
 
 #define DRV_NAME	"sata_mv"
-#define DRV_VERSION	"1.24"
+#define DRV_VERSION	"1.25"
 
 enum {
 	/* BAR's are enumerated in terms of pci_resource_start() terms */
@@ -351,8 +347,6 @@ enum {
 
 	EDMA_HALTCOND_OFS	= 0x60,		/* GenIIe halt conditions */
 
-	GEN_II_NCQ_MAX_SECTORS	= 256,		/* max sects/io on Gen2 w/NCQ */
-
 	/* Host private flags (hp_flags) */
 	MV_HP_FLAG_MSI		= (1 << 0),
 	MV_HP_ERRATA_50XXB0	= (1 << 1),
@@ -883,19 +877,15 @@ static void mv_start_dma(struct ata_port *ap, void __iomem *port_mmio,
 		struct mv_host_priv *hpriv = ap->host->private_data;
 		int hardport = mv_hardport_from_port(ap->port_no);
 		void __iomem *hc_mmio = mv_hc_base_from_port(
-					mv_host_base(ap->host), hardport);
-		u32 hc_irq_cause, ipending;
+					mv_host_base(ap->host), ap->port_no);
+		u32 hc_irq_cause;
 
 		/* clear EDMA event indicators, if any */
 		writelfl(0, port_mmio + EDMA_ERR_IRQ_CAUSE_OFS);
 
-		/* clear EDMA interrupt indicator, if any */
-		hc_irq_cause = readl(hc_mmio + HC_IRQ_CAUSE_OFS);
-		ipending = (DEV_IRQ | DMA_IRQ) << hardport;
-		if (hc_irq_cause & ipending) {
-			writelfl(hc_irq_cause & ~ipending,
-				 hc_mmio + HC_IRQ_CAUSE_OFS);
-		}
+		/* clear pending irq events */
+		hc_irq_cause = ~((DEV_IRQ | DMA_IRQ) << hardport);
+		writelfl(hc_irq_cause, hc_mmio + HC_IRQ_CAUSE_OFS);
 
 		mv_edma_cfg(ap, want_ncq);
 
@@ -1099,20 +1089,12 @@ static void mv6_dev_config(struct ata_device *adev)
 	 *
 	 * Gen-II does not support NCQ over a port multiplier
 	 *  (no FIS-based switching).
-	 *
-	 * We don't have hob_nsect when doing NCQ commands on Gen-II.
-	 * See mv_qc_prep() for more info.
 	 */
 	if (adev->flags & ATA_DFLAG_NCQ) {
 		if (sata_pmp_attached(adev->link->ap)) {
 			adev->flags &= ~ATA_DFLAG_NCQ;
 			ata_dev_printk(adev, KERN_INFO,
 				"NCQ disabled for command-based switching\n");
-		} else if (adev->max_sectors > GEN_II_NCQ_MAX_SECTORS) {
-			adev->max_sectors = GEN_II_NCQ_MAX_SECTORS;
-			ata_dev_printk(adev, KERN_INFO,
-				"max_sectors limited to %u for NCQ\n",
-				adev->max_sectors);
 		}
 	}
 }
@@ -1450,7 +1432,8 @@ static void mv_qc_prep(struct ata_queued_cmd *qc)
 	 * only 11 bytes...so we must pick and choose required
 	 * registers based on the command.  So, we drop feature and
 	 * hob_feature for [RW] DMA commands, but they are needed for
-	 * NCQ.  NCQ will drop hob_nsect.
+	 * NCQ.  NCQ will drop hob_nsect, which is not needed there
+	 * (nsect is used only for the tag; feat/hob_feat hold true nsect).
 	 */
 	switch (tf->command) {
 	case ATA_CMD_READ:
@@ -2214,9 +2197,15 @@ static irqreturn_t mv_interrupt(int irq, void *dev_instance)
 	struct ata_host *host = dev_instance;
 	struct mv_host_priv *hpriv = host->private_data;
 	unsigned int handled = 0;
+	int using_msi = hpriv->hp_flags & MV_HP_FLAG_MSI;
 	u32 main_irq_cause, pending_irqs;
 
 	spin_lock(&host->lock);
+
+	/* for MSI:  block new interrupts while in here */
+	if (using_msi)
+		writel(0, hpriv->main_irq_mask_addr);
+
 	main_irq_cause = readl(hpriv->main_irq_cause_addr);
 	pending_irqs   = main_irq_cause & hpriv->main_irq_mask;
 	/*
@@ -2230,6 +2219,11 @@ static irqreturn_t mv_interrupt(int irq, void *dev_instance)
 			handled = mv_host_intr(host, pending_irqs);
 	}
 	spin_unlock(&host->lock);
+
+	/* for MSI: unmask; interrupt cause bits will retrigger now */
+	if (using_msi)
+		writel(hpriv->main_irq_mask, hpriv->main_irq_mask_addr);
+
 	return IRQ_RETVAL(handled);
 }
 
@@ -2821,8 +2815,7 @@ static void mv_eh_thaw(struct ata_port *ap)
 	writel(0, port_mmio + EDMA_ERR_IRQ_CAUSE_OFS);
 
 	/* clear pending irq events */
-	hc_irq_cause = readl(hc_mmio + HC_IRQ_CAUSE_OFS);
-	hc_irq_cause &= ~((DEV_IRQ | DMA_IRQ) << hardport);
+	hc_irq_cause = ~((DEV_IRQ | DMA_IRQ) << hardport);
 	writelfl(hc_irq_cause, hc_mmio + HC_IRQ_CAUSE_OFS);
 
 	mv_enable_port_irqs(ap, ERR_IRQ);
@@ -3075,6 +3068,9 @@ static int mv_init_host(struct ata_host *host, unsigned int board_idx)
 		hpriv->main_irq_mask_addr  = mmio + PCI_HC_MAIN_IRQ_MASK_OFS;
 	}
 
+	/* initialize shadow irq mask with register's value */
+	hpriv->main_irq_mask = readl(hpriv->main_irq_mask_addr);
+
 	/* global interrupt mask: 0 == mask everything */
 	mv_set_main_irq_mask(host, ~0, 0);
 
@@ -3430,9 +3426,9 @@ static int mv_pci_init_one(struct pci_dev *pdev,
 	if (rc)
 		return rc;
 
-	/* Enable interrupts */
-	if (msi && pci_enable_msi(pdev))
-		pci_intx(pdev, 1);
+	/* Enable message-switched interrupts, if requested */
+	if (msi && pci_enable_msi(pdev) == 0)
+		hpriv->hp_flags |= MV_HP_FLAG_MSI;
 
 	mv_dump_pci_cfg(pdev, 0x68);
 	mv_print_info(host);