libata-core/sff: Fix multiple assumptions about DMA

[pandora-kernel.git] / drivers / ata / libata-sff.c

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index e35d134..ce84805 100644 (file)
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -80,25 +80,25 @@ u8 ata_dummy_irq_on (struct ata_port *ap)   { return 0; }
 u8 ata_irq_ack(struct ata_port *ap, unsigned int chk_drq)
 {
        unsigned int bits = chk_drq ? ATA_BUSY | ATA_DRQ : ATA_BUSY;
-       u8 host_stat, post_stat, status;
+       u8 host_stat = 0, post_stat = 0, status;
 
        status = ata_busy_wait(ap, bits, 1000);
        if (status & bits)
                if (ata_msg_err(ap))
                        printk(KERN_ERR "abnormal status 0x%X\n", status);
 
-       /* get controller status; clear intr, err bits */
-       host_stat = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
-       iowrite8(host_stat | ATA_DMA_INTR | ATA_DMA_ERR,
-                ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
-
-       post_stat = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+       if (ap->ioaddr.bmdma_addr) {
+               /* get controller status; clear intr, err bits */
+               host_stat = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+               iowrite8(host_stat | ATA_DMA_INTR | ATA_DMA_ERR,
+                        ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
 
+               post_stat = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+       }
        if (ata_msg_intr(ap))
                printk(KERN_INFO "%s: irq ack: host_stat 0x%X, new host_stat 0x%X, drv_stat 0x%X\n",
                        __FUNCTION__,
                        host_stat, post_stat, status);
-
        return status;
 }
 
@@ -516,6 +516,27 @@ void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
                ata_bmdma_stop(qc);
 }
 
+/**
+ *     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;
+}
+
 #ifdef CONFIG_PCI
 
 static int ata_resources_present(struct pci_dev *pdev, int port)