1 files changed, 125 insertions, 1 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 99037a4860d9..33ac5ea4f531 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2536,6 +2536,80 @@ int ata_eh_reset(struct ata_link *link, int classify,
 	goto retry;
 }
 
+static inline void ata_eh_pull_park_action(struct ata_port *ap)
+{
+	struct ata_link *link;
+	struct ata_device *dev;
+	unsigned long flags;
+
+	/*
+	 * This function can be thought of as an extended version of
+	 * ata_eh_about_to_do() specially crafted to accommodate the
+	 * requirements of ATA_EH_PARK handling. Since the EH thread
+	 * does not leave the do {} while () loop in ata_eh_recover as
+	 * long as the timeout for a park request to *one* device on
+	 * the port has not expired, and since we still want to pick
+	 * up park requests to other devices on the same port or
+	 * timeout updates for the same device, we have to pull
+	 * ATA_EH_PARK actions from eh_info into eh_context.i
+	 * ourselves at the beginning of each pass over the loop.
+	 *
+	 * Additionally, all write accesses to &ap->park_req_pending
+	 * through INIT_COMPLETION() (see below) or complete_all()
+	 * (see ata_scsi_park_store()) are protected by the host lock.
+	 * As a result we have that park_req_pending.done is zero on
+	 * exit from this function, i.e. when ATA_EH_PARK actions for
+	 * *all* devices on port ap have been pulled into the
+	 * respective eh_context structs. If, and only if,
+	 * park_req_pending.done is non-zero by the time we reach
+	 * wait_for_completion_timeout(), another ATA_EH_PARK action
+	 * has been scheduled for at least one of the devices on port
+	 * ap and we have to cycle over the do {} while () loop in
+	 * ata_eh_recover() again.
+	 */
+
+	spin_lock_irqsave(ap->lock, flags);
+	INIT_COMPLETION(ap->park_req_pending);
+	ata_port_for_each_link(link, ap) {
+		ata_link_for_each_dev(dev, link) {
+			struct ata_eh_info *ehi = &link->eh_info;
+
+			link->eh_context.i.dev_action[dev->devno] |=
+				ehi->dev_action[dev->devno] & ATA_EH_PARK;
+			ata_eh_clear_action(link, dev, ehi, ATA_EH_PARK);
+		}
+	}
+	spin_unlock_irqrestore(ap->lock, flags);
+}
+
+static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
+{
+	struct ata_eh_context *ehc = &dev->link->eh_context;
+	struct ata_taskfile tf;
+	unsigned int err_mask;
+
+	ata_tf_init(dev, &tf);
+	if (park) {
+		ehc->unloaded_mask |= 1 << dev->devno;
+		tf.command = ATA_CMD_IDLEIMMEDIATE;
+		tf.feature = 0x44;
+		tf.lbal = 0x4c;
+		tf.lbam = 0x4e;
+		tf.lbah = 0x55;
+	} else {
+		ehc->unloaded_mask &= ~(1 << dev->devno);
+		tf.command = ATA_CMD_CHK_POWER;
+	}
+
+	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+	tf.protocol |= ATA_PROT_NODATA;
+	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
+	if (park && (err_mask || tf.lbal != 0xc4)) {
+		ata_dev_printk(dev, KERN_ERR, "head unload failed!\n");
+		ehc->unloaded_mask &= ~(1 << dev->devno);
+	}
+}
+
 static int ata_eh_revalidate_and_attach(struct ata_link *link,
 					struct ata_device **r_failed_dev)
 {
@@ -2845,7 +2919,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	struct ata_device *dev;
 	int nr_failed_devs;
 	int rc;
-	unsigned long flags;
+	unsigned long flags, deadline;
 
 	DPRINTK("ENTER\n");
 
@@ -2919,6 +2993,56 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		}
 	}
 
+	do {
+		unsigned long now;
+
+		/*
+		 * clears ATA_EH_PARK in eh_info and resets
+		 * ap->park_req_pending
+		 */
+		ata_eh_pull_park_action(ap);
+
+		deadline = jiffies;
+		ata_port_for_each_link(link, ap) {
+			ata_link_for_each_dev(dev, link) {
+				struct ata_eh_context *ehc = &link->eh_context;
+				unsigned long tmp;
+
+				if (dev->class != ATA_DEV_ATA)
+					continue;
+				if (!(ehc->i.dev_action[dev->devno] &
+				      ATA_EH_PARK))
+					continue;
+				tmp = dev->unpark_deadline;
+				if (time_before(deadline, tmp))
+					deadline = tmp;
+				else if (time_before_eq(tmp, jiffies))
+					continue;
+				if (ehc->unloaded_mask & (1 << dev->devno))
+					continue;
+
+				ata_eh_park_issue_cmd(dev, 1);
+			}
+		}
+
+		now = jiffies;
+		if (time_before_eq(deadline, now))
+			break;
+
+		deadline = wait_for_completion_timeout(&ap->park_req_pending,
+						       deadline - now);
+	} while (deadline);
+	ata_port_for_each_link(link, ap) {
+		ata_link_for_each_dev(dev, link) {
+			if (!(link->eh_context.unloaded_mask &
+			      (1 << dev->devno)))
+				continue;
+
+			ata_eh_park_issue_cmd(dev, 0);
+			ata_eh_done(link, dev, ATA_EH_PARK);
+		}
+	}
+
 	/* the rest */
 	ata_port_for_each_link(link, ap) {
 		struct ata_eh_context *ehc = &link->eh_context;