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authorAlan Cox <alan@redhat.com>2009-03-24 11:23:46 +0100
committerJeff Garzik <jgarzik@redhat.com>2009-03-25 03:52:39 +0100
commitc96f1732e25362d10ee7bcac1df8412a2e6b7d23 (patch)
tree66e24eddb174d6751579ec5952f72cbbac0fb038 /drivers/ata/libata-sff.c
parent[libata] Drain data on errors (diff)
downloadlinux-c96f1732e25362d10ee7bcac1df8412a2e6b7d23.tar.xz
linux-c96f1732e25362d10ee7bcac1df8412a2e6b7d23.zip
[libata] Improve timeout handling
On a timeout call a device specific handler early in the recovery so that we can complete and process successful commands which timed out due to IRQ loss or the like rather more elegantly. [Revised to exclude the timeout handling on a few devices that inherit from SFF but are not SFF enough to use the default timeout handler] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/libata-sff.c')
-rw-r--r--drivers/ata/libata-sff.c46
1 files changed, 45 insertions, 1 deletions
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 9a10cb055ac2..8332e97a9de3 100644
--- 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;
@@ -1776,6 +1778,48 @@ 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
*