---

yaml
---
r: 42106
b: refs/heads/master
c: 55a8e2c
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bff0464769f2a1bd348265de704471747378e247
+refs/heads/master: 55a8e2c83ce50548dfef74bb19dfe2b809cb3099

trunk/drivers/ata/libata-core.c

@@ -1272,9 +1272,20 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
 
 	tf.protocol = ATA_PROT_PIO;
 
+	/* presence detection using polling IDENTIFY? */
+	if (flags & ATA_READID_DETECT)
+		tf.flags |= ATA_TFLAG_POLLING;
+
 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
 				     id, sizeof(id[0]) * ATA_ID_WORDS);
 	if (err_mask) {
+		if ((flags & ATA_READID_DETECT) &&
+		    (err_mask & AC_ERR_NODEV_HINT)) {
+			DPRINTK("ata%u.%d: NODEV after polling detection\n",
+				ap->id, dev->devno);
+			return -ENOENT;
+		}
+
 		rc = -EIO;
 		reason = "I/O error";
 		goto err_out;
@@ -4285,8 +4296,12 @@ int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
 					/* device stops HSM for abort/error */
 					qc->err_mask |= AC_ERR_DEV;
 				else
-					/* HSM violation. Let EH handle this */
-					qc->err_mask |= AC_ERR_HSM;
+					/* HSM violation. Let EH handle this.
+					 * Phantom devices also trigger this
+					 * condition.  Mark hint.
+					 */
+					qc->err_mask |= AC_ERR_HSM |
+							AC_ERR_NODEV_HINT;
 
 				ap->hsm_task_state = HSM_ST_ERR;
 				goto fsm_start;

trunk/drivers/ata/libata-eh.c

@@ -1667,25 +1667,38 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
 			   ata_class_enabled(ehc->classes[dev->devno])) {
 			dev->class = ehc->classes[dev->devno];
 
+			if (ap->flags & ATA_FLAG_DETECT_POLLING)
+				readid_flags |= ATA_READID_DETECT;
+
 			rc = ata_dev_read_id(dev, &dev->class, readid_flags,
 					     dev->id);
 			if (rc == 0) {
 				ehc->i.flags |= ATA_EHI_PRINTINFO;
 				rc = ata_dev_configure(dev);
 				ehc->i.flags &= ~ATA_EHI_PRINTINFO;
+			} else if (rc == -ENOENT) {
+				/* IDENTIFY was issued to non-existent
+				 * device.  No need to reset.  Just
+				 * thaw and kill the device.
+				 */
+				ata_eh_thaw_port(ap);
+				dev->class = ATA_DEV_UNKNOWN;
+				rc = 0;
 			}
 
 			if (rc) {
 				dev->class = ATA_DEV_UNKNOWN;
 				break;
 			}
 
-			spin_lock_irqsave(ap->lock, flags);
-			ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
-			spin_unlock_irqrestore(ap->lock, flags);
+			if (ata_dev_enabled(dev)) {
+				spin_lock_irqsave(ap->lock, flags);
+				ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
+				spin_unlock_irqrestore(ap->lock, flags);
 
-			/* new device discovered, configure transfer mode */
-			ehc->i.flags |= ATA_EHI_SETMODE;
+				/* new device discovered, configure xfermode */
+				ehc->i.flags |= ATA_EHI_SETMODE;
+			}
 		}
 	}
 

trunk/drivers/ata/libata.h

@@ -42,6 +42,8 @@ struct ata_scsi_args {
 enum {
 	/* flags for ata_dev_read_id() */
 	ATA_READID_POSTRESET	= (1 << 0), /* reading ID after reset */
+	ATA_READID_DETECT	= (1 << 1), /* perform presence detection
+					     * using polling IDENTIFY */
 };
 
 extern struct workqueue_struct *ata_aux_wq;

trunk/include/linux/libata.h

@@ -176,6 +176,8 @@ enum {
 	ATA_FLAG_SKIP_D2H_BSY	= (1 << 12), /* can't wait for the first D2H
 					      * Register FIS clearing BSY */
 	ATA_FLAG_DEBUGMSG	= (1 << 13),
+	ATA_FLAG_DETECT_POLLING	= (1 << 14), /* detect device presence by
+					      * polling IDENTIFY */
 
 	/* The following flag belongs to ap->pflags but is kept in
 	 * ap->flags because it's referenced in many LLDs and will be
@@ -335,6 +337,7 @@ enum ata_completion_errors {
 	AC_ERR_SYSTEM		= (1 << 6), /* system error */
 	AC_ERR_INVALID		= (1 << 7), /* invalid argument */
 	AC_ERR_OTHER		= (1 << 8), /* unknown */
+	AC_ERR_NODEV_HINT	= (1 << 9), /* polling device detection hint */
 };
 
 /* forward declarations */