1 files changed, 44 insertions, 10 deletions

diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index cb46ce276bb1..b2817a2995d6 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -900,14 +900,52 @@ static const char *ata_lpm_policy_names[] = {
 	[ATA_LPM_MIN_POWER]		= "min_power",
 };
 
+/*
+ * Check if a port supports link power management.
+ * Must be called with the port locked.
+ */
+static bool ata_scsi_lpm_supported(struct ata_port *ap)
+{
+	struct ata_link *link;
+	struct ata_device *dev;
+
+	if (ap->flags & ATA_FLAG_NO_LPM)
+		return false;
+
+	ata_for_each_link(link, ap, EDGE) {
+		ata_for_each_dev(dev, &ap->link, ENABLED) {
+			if (dev->quirks & ATA_QUIRK_NOLPM)
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static ssize_t ata_scsi_lpm_supported_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	unsigned long flags;
+	bool supported;
+
+	spin_lock_irqsave(ap->lock, flags);
+	supported = ata_scsi_lpm_supported(ap);
+	spin_unlock_irqrestore(ap->lock, flags);
+
+	return sysfs_emit(buf, "%d\n", supported);
+}
+DEVICE_ATTR(link_power_management_supported, S_IRUGO,
+	    ata_scsi_lpm_supported_show, NULL);
+EXPORT_SYMBOL_GPL(dev_attr_link_power_management_supported);
+
 static ssize_t ata_scsi_lpm_store(struct device *device,
 				  struct device_attribute *attr,
 				  const char *buf, size_t count)
 {
 	struct Scsi_Host *shost = class_to_shost(device);
 	struct ata_port *ap = ata_shost_to_port(shost);
-	struct ata_link *link;
-	struct ata_device *dev;
 	enum ata_lpm_policy policy;
 	unsigned long flags;
 
@@ -924,13 +962,9 @@ static ssize_t ata_scsi_lpm_store(struct device *device,
 
 	spin_lock_irqsave(ap->lock, flags);
 
-	ata_for_each_link(link, ap, EDGE) {
-		ata_for_each_dev(dev, &ap->link, ENABLED) {
-			if (dev->quirks & ATA_QUIRK_NOLPM) {
-				count = -EOPNOTSUPP;
-				goto out_unlock;
-			}
-		}
+	if (!ata_scsi_lpm_supported(ap)) {
+		count = -EOPNOTSUPP;
+		goto out_unlock;
 	}
 
 	ap->target_lpm_policy = policy;
@@ -1699,6 +1733,6 @@ const struct ata_port_operations sata_port_ops = {
 	.inherits		= &ata_base_port_ops,
 
 	.qc_defer		= ata_std_qc_defer,
-	.hardreset		= sata_std_hardreset,
+	.reset.hardreset	= sata_std_hardreset,
 };
 EXPORT_SYMBOL_GPL(sata_port_ops);