1 files changed, 26 insertions, 30 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 86918634a4c5..f2d8a020ea53 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);