[libata] Improve timeout handling

[linux-2.6-omap-h63xx.git] / drivers / ata / libata-sff.c

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 9a10cb055ac2e554c6025cc35bd5c40677df3cce..8332e97a9de38026ea33b39799f1cf16c1d3837e 100644 (file)
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -65,6 +65,8 @@ const struct ata_port_operations ata_sff_port_ops = {
        .sff_irq_on             = ata_sff_irq_on,
        .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);
@@ -1647,7 +1649,7 @@ EXPORT_SYMBOL_GPL(ata_sff_qc_fill_rtf);
  *     RETURNS:
  *     One if interrupt was handled, zero if not (shared irq).
  */
-inline unsigned int ata_sff_host_intr(struct ata_port *ap,
+unsigned int ata_sff_host_intr(struct ata_port *ap,
                                      struct ata_queued_cmd *qc)
 {
        struct ata_eh_info *ehi = &ap->link.eh_info;
@@ -1775,6 +1777,48 @@ irqreturn_t ata_sff_interrupt(int irq, void *dev_instance)
 }
 EXPORT_SYMBOL_GPL(ata_sff_interrupt);
 
+/**
+ *     ata_sff_lost_interrupt  -       Check for an apparent lost interrupt
+ *     @ap: port that appears to have timed out
+ *
+ *     Called from the libata error handlers when the core code suspects
+ *     an interrupt has been lost. If it has complete anything we can and
+ *     then return. Interface must support altstatus for this faster
+ *     recovery to occur.
+ *
+ *     Locking:
+ *     Caller holds host lock
+ */
+
+void ata_sff_lost_interrupt(struct ata_port *ap)
+{
+       u8 status;
+       struct ata_queued_cmd *qc;
+
+       /* Only one outstanding command per SFF channel */
+       qc = ata_qc_from_tag(ap, ap->link.active_tag);
+       /* Check we have a live one.. */
+       if (qc == NULL ||  !(qc->flags & ATA_QCFLAG_ACTIVE))
+               return;
+       /* We cannot lose an interrupt on a polled command */
+       if (qc->tf.flags & ATA_TFLAG_POLLING)
+               return;
+       /* See if the controller thinks it is still busy - if so the command
+          isn't a lost IRQ but is still in progress */
+       status = ata_sff_altstatus(ap);
+       if (status & ATA_BUSY)
+               return;
+
+       /* There was a command running, we are no longer busy and we have
+          no interrupt. */
+       ata_port_printk(ap, KERN_WARNING, "lost interrupt (Status 0x%x)\n",
+                                                               status);
+       /* Run the host interrupt logic as if the interrupt had not been
+          lost */
+       ata_sff_host_intr(ap, qc);
+}
+EXPORT_SYMBOL_GPL(ata_sff_lost_interrupt);
+
 /**
  *     ata_sff_freeze - Freeze SFF controller port
  *     @ap: port to freeze