[PATCH] libata irq-pio: add comments and cleanup

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/scsi/libata-core.c

@@ -3430,18 +3430,6 @@ int ata_qc_issue_prot(struct ata_queued_cmd *qc)
 		break;
 
 	case ATA_PROT_ATAPI:
-		if (qc->tf.flags & ATA_TFLAG_POLLING)
-			ata_qc_set_polling(qc);
-
-		ata_tf_to_host_nolock(ap, &qc->tf);
-		ap->hsm_task_state = HSM_ST_FIRST;
-
-		/* send cdb by polling if no cdb interrupt */
-		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
-		    (qc->tf.flags & ATA_TFLAG_POLLING))
-			queue_work(ata_wq, &ap->packet_task);
-		break;
-
 	case ATA_PROT_ATAPI_NODATA:
 		if (qc->tf.flags & ATA_TFLAG_POLLING)
 			ata_qc_set_polling(qc);

include/linux/libata.h

@@ -158,15 +158,16 @@ enum {
 };
 
 enum hsm_task_states {
-	HSM_ST_UNKNOWN,
-	HSM_ST_IDLE,
-	HSM_ST_POLL,
-	HSM_ST_TMOUT,
-	HSM_ST,
-	HSM_ST_LAST,
-	HSM_ST_LAST_POLL,
-	HSM_ST_ERR,
-	HSM_ST_FIRST,
+	HSM_ST_UNKNOWN,		/* state unknown */
+	HSM_ST_IDLE,		/* no command on going */
+	HSM_ST_POLL,		/* same as HSM_ST, waits longer */
+	HSM_ST_TMOUT,		/* timeout */
+	HSM_ST,			/* (waiting the device to) transfer data */
+	HSM_ST_LAST,		/* (waiting the device to) complete command */
+	HSM_ST_LAST_POLL,	/* same as HSM_ST_LAST, waits longer */
+	HSM_ST_ERR,		/* error */
+	HSM_ST_FIRST,		/* (waiting the device to)
+				   write CDB or first data block */
 };
 
 /* forward declarations */