[PATCH] libata-hp: implement bootplug

Implement bootplug - boot probing via hotplug path.  While loading,
ata_host_add() simply schedules probing and invokes EH.  After EH
completes, ata_host_add() scans and assicates them with SCSI devices.
EH path is slightly modified to handle this (e.g. no autopsy during
bootplug).  The SCSI part is left in ata_host_add() because it's
shared with legacy path and to keep probing order as before (ATA scan
all ports in host_set then attach all).

Signed-off-by: Tejun Heo <htejun@gmail.com>

drivers/scsi/libata-core.c

@@ -5419,7 +5419,7 @@ static struct ata_port * ata_host_add(const struct ata_probe_ent *ent,
 
 	DPRINTK("ENTER\n");
 
-	if (!ent->port_ops->probe_reset &&
+	if (!ent->port_ops->probe_reset && !ent->port_ops->error_handler &&
 	    !(ent->host_flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST))) {
 		printk(KERN_ERR "ata%u: no reset mechanism available\n",
 		       port_no);
@@ -5465,7 +5465,6 @@ err_out:
  *	RETURNS:
  *	Number of ports registered.  Zero on error (no ports registered).
  */
-
 int ata_device_add(const struct ata_probe_ent *ent)
 {
 	unsigned int count = 0, i;
@@ -5542,19 +5541,6 @@ int ata_device_add(const struct ata_probe_ent *ent)
 		}
 		ap->sata_spd_limit = ap->hw_sata_spd_limit;
 
-		DPRINTK("ata%u: bus probe begin\n", ap->id);
-		rc = ata_bus_probe(ap);
-		DPRINTK("ata%u: bus probe end\n", ap->id);
-
-		if (rc) {
-			/* FIXME: do something useful here?
-			 * Current libata behavior will
-			 * tear down everything when
-			 * the module is removed
-			 * or the h/w is unplugged.
-			 */
-		}
-
 		rc = scsi_add_host(ap->host, dev);
 		if (rc) {
 			ata_port_printk(ap, KERN_ERR, "scsi_add_host failed\n");
@@ -5564,6 +5550,39 @@ int ata_device_add(const struct ata_probe_ent *ent)
 			 * at the very least
 			 */
 		}
+
+		if (!ap->ops->probe_reset) {
+			unsigned long flags;
+
+			ata_port_probe(ap);
+
+			/* kick EH for boot probing */
+			spin_lock_irqsave(&ap->host_set->lock, flags);
+
+			ap->eh_info.probe_mask = (1 << ATA_MAX_DEVICES) - 1;
+			ap->eh_info.action |= ATA_EH_SOFTRESET;
+
+			ap->flags |= ATA_FLAG_LOADING;
+			ata_port_schedule_eh(ap);
+
+			spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+			/* wait for EH to finish */
+			ata_port_wait_eh(ap);
+		} else {
+			DPRINTK("ata%u: bus probe begin\n", ap->id);
+			rc = ata_bus_probe(ap);
+			DPRINTK("ata%u: bus probe end\n", ap->id);
+
+			if (rc) {
+				/* FIXME: do something useful here?
+				 * Current libata behavior will
+				 * tear down everything when
+				 * the module is removed
+				 * or the h/w is unplugged.
+				 */
+			}
+		}
 	}
 
 	/* probes are done, now scan each port's disk(s) */

drivers/scsi/libata-eh.c

@@ -287,11 +287,14 @@ void ata_scsi_error(struct Scsi_Host *host)
 	/* clean up */
 	spin_lock_irqsave(hs_lock, flags);
 
-	if (ap->flags & ATA_FLAG_SCSI_HOTPLUG)
-		queue_work(ata_aux_wq, &ap->hotplug_task);
-
-	if (ap->flags & ATA_FLAG_RECOVERED)
-		ata_port_printk(ap, KERN_INFO, "EH complete\n");
+	if (ap->flags & ATA_FLAG_LOADING) {
+		ap->flags &= ~ATA_FLAG_LOADING;
+	} else {
+		if (ap->flags & ATA_FLAG_SCSI_HOTPLUG)
+			queue_work(ata_aux_wq, &ap->hotplug_task);
+		if (ap->flags & ATA_FLAG_RECOVERED)
+			ata_port_printk(ap, KERN_INFO, "EH complete\n");
+	}
 
 	ap->flags &= ~(ATA_FLAG_SCSI_HOTPLUG | ATA_FLAG_RECOVERED);
 
@@ -1367,6 +1370,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
 	struct ata_eh_context *ehc = &ap->eh_context;
 	unsigned int *classes = ehc->classes;
 	int tries = ATA_EH_RESET_TRIES;
+	int verbose = !(ap->flags & ATA_FLAG_LOADING);
 	unsigned int action;
 	ata_reset_fn_t reset;
 	int i, did_followup_srst, rc;
@@ -1414,8 +1418,10 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
 	}
 
  retry:
-	ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
-			reset == softreset ? "soft" : "hard");
+	/* shut up during boot probing */
+	if (verbose)
+		ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
+				reset == softreset ? "soft" : "hard");
 
 	/* reset */
 	ata_eh_about_to_do(ap, ATA_EH_RESET_MASK);
@@ -1799,8 +1805,11 @@ void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
 	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
 	       ata_postreset_fn_t postreset)
 {
-	ata_eh_autopsy(ap);
-	ata_eh_report(ap);
+	if (!(ap->flags & ATA_FLAG_LOADING)) {
+		ata_eh_autopsy(ap);
+		ata_eh_report(ap);
+	}
+
 	ata_eh_recover(ap, prereset, softreset, hardreset, postreset);
 	ata_eh_finish(ap);
 }