1 files changed, 84 insertions, 86 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 6400e8751391..f1c99a3e8b2c 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -66,8 +66,6 @@ const struct ata_port_operations ata_sff_port_ops = {
         .sff_irq_clear          = ata_sff_irq_clear,
 
         .lost_interrupt         = ata_sff_lost_interrupt,
-
-        .port_start             = ata_sff_port_start,
 };
 EXPORT_SYMBOL_GPL(ata_sff_port_ops);
 
@@ -2444,50 +2442,6 @@ void ata_sff_post_internal_cmd(struct ata_queued_cmd *qc)
 EXPORT_SYMBOL_GPL(ata_sff_post_internal_cmd);
 
 /**
- *      ata_sff_port_start - Set port up for dma.
- *      @ap: Port to initialize
- *
- *      Called just after data structures for each port are
- *      initialized.  Allocates space for PRD table if the device
- *      is DMA capable SFF.
- *
- *      May be used as the port_start() entry in ata_port_operations.
- *
- *      LOCKING:
- *      Inherited from caller.
- */
-int ata_sff_port_start(struct ata_port *ap)
-{
-        if (ap->ioaddr.bmdma_addr)
-                return ata_port_start(ap);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(ata_sff_port_start);
-
-/**
- *      ata_sff_port_start32 - Set port up for dma.
- *      @ap: Port to initialize
- *
- *      Called just after data structures for each port are
- *      initialized.  Allocates space for PRD table if the device
- *      is DMA capable SFF.
- *
- *      May be used as the port_start() entry in ata_port_operations for
- *      devices that are capable of 32bit PIO.
- *
- *      LOCKING:
- *      Inherited from caller.
- */
-int ata_sff_port_start32(struct ata_port *ap)
-{
-        ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
-        if (ap->ioaddr.bmdma_addr)
-                return ata_port_start(ap);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(ata_sff_port_start32);
-
-/**
  *      ata_sff_std_ports - initialize ioaddr with standard port offsets.
  *      @ioaddr: IO address structure to be initialized
  *
@@ -2646,21 +2600,12 @@ int ata_pci_sff_prepare_host(struct pci_dev *pdev,
                 goto err_out;
 
         /* init DMA related stuff */
-        rc = ata_pci_bmdma_init(host);
-        if (rc)
-                goto err_bmdma;
+        ata_pci_bmdma_init(host);
 
         devres_remove_group(&pdev->dev, NULL);
         *r_host = host;
         return 0;
 
-err_bmdma:
-        /* This is necessary because PCI and iomap resources are
-         * merged and releasing the top group won't release the
-         * acquired resources if some of those have been acquired
-         * before entering this function.
-         */
-        pcim_iounmap_regions(pdev, 0xf);
 err_out:
         devres_release_group(&pdev->dev, NULL);
         return rc;
@@ -2843,12 +2788,12 @@ EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
 const struct ata_port_operations ata_bmdma_port_ops = {
         .inherits               = &ata_sff_port_ops,
 
-        .mode_filter            = ata_bmdma_mode_filter,
-
         .bmdma_setup            = ata_bmdma_setup,
         .bmdma_start            = ata_bmdma_start,
         .bmdma_stop             = ata_bmdma_stop,
         .bmdma_status           = ata_bmdma_status,
+
+        .port_start             = ata_bmdma_port_start,
 };
 EXPORT_SYMBOL_GPL(ata_bmdma_port_ops);
 
@@ -2856,22 +2801,10 @@ const struct ata_port_operations ata_bmdma32_port_ops = {
         .inherits               = &ata_bmdma_port_ops,
 
         .sff_data_xfer          = ata_sff_data_xfer32,
-        .port_start             = ata_sff_port_start32,
+        .port_start             = ata_bmdma_port_start32,
 };
 EXPORT_SYMBOL_GPL(ata_bmdma32_port_ops);
 
-unsigned long ata_bmdma_mode_filter(struct ata_device *adev,
-                                    unsigned long xfer_mask)
-{
-        /* Filter out DMA modes if the device has been configured by
-           the BIOS as PIO only */
-
-        if (adev->link->ap->ioaddr.bmdma_addr == NULL)
-                xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
-        return xfer_mask;
-}
-EXPORT_SYMBOL_GPL(ata_bmdma_mode_filter);
-
 /**
  *      ata_bmdma_setup - Set up PCI IDE BMDMA transaction
  *      @qc: Info associated with this ATA transaction.
@@ -2976,6 +2909,53 @@ u8 ata_bmdma_status(struct ata_port *ap)
 }
 EXPORT_SYMBOL_GPL(ata_bmdma_status);
 
+
+/**
+ *      ata_bmdma_port_start - Set port up for bmdma.
+ *      @ap: Port to initialize
+ *
+ *      Called just after data structures for each port are
+ *      initialized.  Allocates space for PRD table.
+ *
+ *      May be used as the port_start() entry in ata_port_operations.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+int ata_bmdma_port_start(struct ata_port *ap)
+{
+        if (ap->mwdma_mask || ap->udma_mask) {
+                ap->prd = dmam_alloc_coherent(ap->host->dev, ATA_PRD_TBL_SZ,
+                                              &ap->prd_dma, GFP_KERNEL);
+                if (!ap->prd)
+                        return -ENOMEM;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(ata_bmdma_port_start);
+
+/**
+ *      ata_bmdma_port_start32 - Set port up for dma.
+ *      @ap: Port to initialize
+ *
+ *      Called just after data structures for each port are
+ *      initialized.  Enables 32bit PIO and allocates space for PRD
+ *      table.
+ *
+ *      May be used as the port_start() entry in ata_port_operations for
+ *      devices that are capable of 32bit PIO.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+int ata_bmdma_port_start32(struct ata_port *ap)
+{
+        ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
+        return ata_bmdma_port_start(ap);
+}
+EXPORT_SYMBOL_GPL(ata_bmdma_port_start32);
+
 #ifdef CONFIG_PCI
 
 /**
@@ -3004,6 +2984,19 @@ int ata_pci_bmdma_clear_simplex(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL_GPL(ata_pci_bmdma_clear_simplex);
 
+static void ata_bmdma_nodma(struct ata_host *host, const char *reason)
+{
+        int i;
+
+        dev_printk(KERN_ERR, host->dev, "BMDMA: %s, falling back to PIO\n",
+                   reason);
+
+        for (i = 0; i < 2; i++) {
+                host->ports[i]->mwdma_mask = 0;
+                host->ports[i]->udma_mask = 0;
+        }
+}
+
 /**
  *      ata_pci_bmdma_init - acquire PCI BMDMA resources and init ATA host
  *      @host: target ATA host
@@ -3012,33 +3005,40 @@ EXPORT_SYMBOL_GPL(ata_pci_bmdma_clear_simplex);
  *
  *      LOCKING:
  *      Inherited from calling layer (may sleep).
- *
- *      RETURNS:
- *      0 on success, -errno otherwise.
  */
-int ata_pci_bmdma_init(struct ata_host *host)
+void ata_pci_bmdma_init(struct ata_host *host)
 {
         struct device *gdev = host->dev;
         struct pci_dev *pdev = to_pci_dev(gdev);
         int i, rc;
 
         /* No BAR4 allocation: No DMA */
-        if (pci_resource_start(pdev, 4) == 0)
-                return 0;
+        if (pci_resource_start(pdev, 4) == 0) {
+                ata_bmdma_nodma(host, "BAR4 is zero");
+                return;
+        }
 
-        /* TODO: If we get no DMA mask we should fall back to PIO */
+        /*
+         * Some controllers require BMDMA region to be initialized
+         * even if DMA is not in use to clear IRQ status via
+         * ->sff_irq_clear method.  Try to initialize bmdma_addr
+         * regardless of dma masks.
+         */
         rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
         if (rc)
-                return rc;
-        rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
-        if (rc)
-                return rc;
+                ata_bmdma_nodma(host, "failed to set dma mask");
+        if (!rc) {
+                rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
+                if (rc)
+                        ata_bmdma_nodma(host,
+                                        "failed to set consistent dma mask");
+        }
 
         /* request and iomap DMA region */
         rc = pcim_iomap_regions(pdev, 1 << 4, dev_driver_string(gdev));
         if (rc) {
-                dev_printk(KERN_ERR, gdev, "failed to request/iomap BAR4\n");
-                return -ENOMEM;
+                ata_bmdma_nodma(host, "failed to request/iomap BAR4");
+                return;
         }
         host->iomap = pcim_iomap_table(pdev);
 
@@ -3057,8 +3057,6 @@ int ata_pci_bmdma_init(struct ata_host *host)
                 ata_port_desc(ap, "bmdma 0x%llx",
                     (unsigned long long)pci_resource_start(pdev, 4) + 8 * i);
         }
-
-        return 0;
 }
 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init);