[PATCH] libata-dev: Convert ata_pio_task() to use the new ata_hsm_move()
Convert ata_pio_task() to use the new ata_hsm_move().
Changes:
- refactor ata_pio_task() to poll device status register and
- call the new ata_hsm_move() when device indicates it is not BSY.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 33b39d3..eeeeda0 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -3986,44 +3986,40 @@
static void ata_pio_task(void *_data)
{
struct ata_port *ap = _data;
- unsigned long timeout;
- int has_next;
+ struct ata_queued_cmd *qc;
+ u8 status;
+ int poll_next;
fsm_start:
- timeout = 0;
- has_next = 1;
+ WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
- switch (ap->hsm_task_state) {
- case HSM_ST_FIRST:
- has_next = ata_pio_first_block(ap);
- break;
+ qc = ata_qc_from_tag(ap, ap->active_tag);
+ WARN_ON(qc == NULL);
- case HSM_ST:
- ata_pio_block(ap);
- break;
-
- case HSM_ST_LAST:
- has_next = ata_pio_complete(ap);
- break;
-
- case HSM_ST_POLL:
- case HSM_ST_LAST_POLL:
- timeout = ata_pio_poll(ap);
- break;
-
- case HSM_ST_TMOUT:
- case HSM_ST_ERR:
- ata_pio_error(ap);
- return;
-
- default:
- BUG();
- return;
+ /*
+ * This is purely heuristic. This is a fast path.
+ * Sometimes when we enter, BSY will be cleared in
+ * a chk-status or two. If not, the drive is probably seeking
+ * or something. Snooze for a couple msecs, then
+ * chk-status again. If still busy, queue delayed work.
+ */
+ status = ata_busy_wait(ap, ATA_BUSY, 5);
+ if (status & ATA_BUSY) {
+ msleep(2);
+ status = ata_busy_wait(ap, ATA_BUSY, 10);
+ if (status & ATA_BUSY) {
+ ata_port_queue_task(ap, ata_pio_task, ap, ATA_SHORT_PAUSE);
+ return;
+ }
}
- if (timeout)
- ata_port_queue_task(ap, ata_pio_task, ap, timeout);
- else if (has_next)
+ /* move the HSM */
+ poll_next = ata_hsm_move(ap, qc, status, 1);
+
+ /* another command or interrupt handler
+ * may be running at this point.
+ */
+ if (poll_next)
goto fsm_start;
}