[libata] Drain data on errors

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

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 714cb04..9a10cb0 100644 (file)
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -52,6 +52,7 @@ const struct ata_port_operations ata_sff_port_ops = {
        .softreset              = ata_sff_softreset,
        .hardreset              = sata_sff_hardreset,
        .postreset              = ata_sff_postreset,
+       .drain_fifo             = ata_sff_drain_fifo,
        .error_handler          = ata_sff_error_handler,
        .post_internal_cmd      = ata_sff_post_internal_cmd,
 
@@ -2066,6 +2067,7 @@ static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
        iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
        udelay(20);     /* FIXME: flush */
        iowrite8(ap->ctl, ioaddr->ctl_addr);
+       ap->last_ctl = ap->ctl;
 
        /* wait the port to become ready */
        return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
@@ -2190,11 +2192,46 @@ void ata_sff_postreset(struct ata_link *link, unsigned int *classes)
        }
 
        /* set up device control */
-       if (ap->ioaddr.ctl_addr)
+       if (ap->ioaddr.ctl_addr) {
                iowrite8(ap->ctl, ap->ioaddr.ctl_addr);
+               ap->last_ctl = ap->ctl;
+       }
 }
 EXPORT_SYMBOL_GPL(ata_sff_postreset);
 
+/**
+ *     ata_sff_drain_fifo - Stock FIFO drain logic for SFF controllers
+ *     @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
+ *     reset will recover the device.
+ *
+ */
+
+void ata_sff_drain_fifo(struct ata_queued_cmd *qc)
+{
+       int count;
+       struct ata_port *ap;
+
+       /* We only need to flush incoming data when a command was running */
+       if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
+               return;
+
+       ap = qc->ap;
+       /* Drain up to 64K of data before we give up this recovery method */
+       for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
+                                               && count < 32768; count++)
+               ioread16(ap->ioaddr.data_addr);
+
+       /* Can become DEBUG later */
+       if (count)
+               ata_port_printk(ap, KERN_DEBUG,
+                       "drained %d bytes to clear DRQ.\n", count);
+
+}
+EXPORT_SYMBOL_GPL(ata_sff_drain_fifo);
+
 /**
  *     ata_sff_error_handler - Stock error handler for BMDMA controller
  *     @ap: port to handle error for
@@ -2236,7 +2273,8 @@ void ata_sff_error_handler(struct ata_port *ap)
                 * really a timeout event, adjust error mask and
                 * cancel frozen state.
                 */
-               if (qc->err_mask == AC_ERR_TIMEOUT && (host_stat & ATA_DMA_ERR)) {
+               if (qc->err_mask == AC_ERR_TIMEOUT
+                                               && (host_stat & ATA_DMA_ERR)) {
                        qc->err_mask = AC_ERR_HOST_BUS;
                        thaw = 1;
                }
@@ -2247,6 +2285,13 @@ void ata_sff_error_handler(struct ata_port *ap)
        ata_sff_sync(ap);               /* FIXME: We don't need this */
        ap->ops->sff_check_status(ap);
        ap->ops->sff_irq_clear(ap);
+       /* We *MUST* do FIFO draining before we issue a reset as several
+        * devices helpfully clear their internal state and will lock solid
+        * if we touch the data port post reset. Pass qc in case anyone wants
+        *  to do different PIO/DMA recovery or has per command fixups
+        */
+       if (ap->ops->drain_fifo)
+               ap->ops->drain_fifo(qc);
 
        spin_unlock_irqrestore(ap->lock, flags);
 
@@ -2534,6 +2579,7 @@ void ata_bus_reset(struct ata_port *ap)
        if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
                /* set up device control for ATA_FLAG_SATA_RESET */
                iowrite8(ap->ctl, ioaddr->ctl_addr);
+               ap->last_ctl = ap->ctl;
        }
 
        DPRINTK("EXIT\n");
@@ -2955,4 +3001,3 @@ out:
 EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
 
 #endif /* CONFIG_PCI */
-