---

yaml
---
r: 110264
b: refs/heads/master
c: 11fc33d
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d09addf65cb5b3b19a536aa3329efeedbc6bb56c
+refs/heads/master: 11fc33da8d8413d6bfa5143f454dfcb998c27617

trunk/drivers/ata/libata-eh.c

@@ -79,6 +79,8 @@ enum {
 	 */
 	ATA_EH_PRERESET_TIMEOUT		= 10000,
 	ATA_EH_FASTDRAIN_INTERVAL	=  3000,
+
+	ATA_EH_UA_TRIES			= 5,
 };
 
 /* The following table determines how we sequence resets.  Each entry
@@ -1356,6 +1358,37 @@ static int ata_eh_read_log_10h(struct ata_device *dev,
 	return 0;
 }
 
+/**
+ *	atapi_eh_tur - perform ATAPI TEST_UNIT_READY
+ *	@dev: target ATAPI device
+ *	@r_sense_key: out parameter for sense_key
+ *
+ *	Perform ATAPI TEST_UNIT_READY.
+ *
+ *	LOCKING:
+ *	EH context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, AC_ERR_* mask on failure.
+ */
+static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
+{
+	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	ata_tf_init(dev, &tf);
+
+	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
+	tf.command = ATA_CMD_PACKET;
+	tf.protocol = ATAPI_PROT_NODATA;
+
+	err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
+	if (err_mask == AC_ERR_DEV)
+		*r_sense_key = tf.feature >> 4;
+	return err_mask;
+}
+
 /**
  *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
  *	@dev: device to perform REQUEST_SENSE to
@@ -2774,6 +2807,53 @@ int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 	return rc;
 }
 
+/**
+ *	atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
+ *	@dev: ATAPI device to clear UA for
+ *
+ *	Resets and other operations can make an ATAPI device raise
+ *	UNIT ATTENTION which causes the next operation to fail.  This
+ *	function clears UA.
+ *
+ *	LOCKING:
+ *	EH context (may sleep).
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+static int atapi_eh_clear_ua(struct ata_device *dev)
+{
+	int i;
+
+	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
+		u8 sense_buffer[SCSI_SENSE_BUFFERSIZE];
+		u8 sense_key = 0;
+		unsigned int err_mask;
+
+		err_mask = atapi_eh_tur(dev, &sense_key);
+		if (err_mask != 0 && err_mask != AC_ERR_DEV) {
+			ata_dev_printk(dev, KERN_WARNING, "TEST_UNIT_READY "
+				"failed (err_mask=0x%x)\n", err_mask);
+			return -EIO;
+		}
+
+		if (!err_mask || sense_key != UNIT_ATTENTION)
+			return 0;
+
+		err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
+		if (err_mask) {
+			ata_dev_printk(dev, KERN_WARNING, "failed to clear "
+				"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
+			return -EIO;
+		}
+	}
+
+	ata_dev_printk(dev, KERN_WARNING,
+		"UNIT ATTENTION persists after %d tries\n", ATA_EH_UA_TRIES);
+
+	return 0;
+}
+
 static int ata_link_nr_enabled(struct ata_link *link)
 {
 	struct ata_device *dev;
@@ -3066,6 +3146,20 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 			ehc->i.flags &= ~ATA_EHI_SETMODE;
 		}
 
+		/* If reset has been issued, clear UA to avoid
+		 * disrupting the current users of the device.
+		 */
+		if (ehc->i.flags & ATA_EHI_DID_RESET) {
+			ata_link_for_each_dev(dev, link) {
+				if (dev->class != ATA_DEV_ATAPI)
+					continue;
+				rc = atapi_eh_clear_ua(dev);
+				if (rc)
+					goto dev_fail;
+			}
+		}
+
+		/* configure link power saving */
 		if (ehc->i.action & ATA_EH_LPM)
 			ata_link_for_each_dev(dev, link)
 				ata_dev_enable_pm(dev, ap->pm_policy);