Tejun Heo wrote:
Implement port_task. LLDD's can schedule a function to be executed
with context after specified delay. libata core takes care of
synchronization against EH. This is generalized form of pio_task and
packet_task which are tied to PIO hsm implementation.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/libata-core.c | 77 ++++++++++++++++++++++++++++++++++++++++++++
drivers/scsi/libata-scsi.c | 2 +
drivers/scsi/libata.h | 1 +
include/linux/libata.h | 4 ++
4 files changed, 84 insertions(+), 0 deletions(-)
4d83950873856672ed469f25c6421de1eb98ba97
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index b710fc4..3575d68 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -721,6 +721,81 @@ static unsigned int ata_pio_modes(const
timing API will get this right anyway */
}
+/**
+ * ata_port_queue_task - Queue port_task
+ * @ap: The ata_port to queue port_task for
+ *
+ * Schedule @fn(@data) for execution after @delay jiffies using
+ * port_task. There is one port_task per port and it's the
+ * user(low level driver)'s responsibility to make sure that only
+ * one task is active at any given time.
+ *
+ * libata core layer takes care of synchronization between
+ * port_task and EH. ata_port_queue_task() may be ignored for EH
+ * synchronization.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+void ata_port_queue_task(struct ata_port *ap, void (*fn)(void *), void *data,
+ unsigned long delay)
+{
+ int rc;
+
+ if (ap->flags & ATA_FLAG_FLUSH_PIO_TASK)
+ return;
+
+ PREPARE_WORK(&ap->port_task, fn, data);
+
+ if (!delay)
+ rc = queue_work(ata_wq, &ap->port_task);
+ else
+ rc = queue_delayed_work(ata_wq, &ap->port_task, delay);
Two worries here, though not quite a NAK:
1) This is abuse of the PREPARE_WORK(), which is usually not used
because INIT_WORK() took care of the initialization. However, it should
be OK if...
2) This will fall apart if anything tries to queue a task while a
previous task is still pending. Are you certain a double-queue never
ever happens?
Jeff
-
: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
