1 files changed, 25 insertions, 10 deletions

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index c77b6e06bf6..f3c417943da 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -563,14 +563,23 @@ out_unlock:
 	return rc;
 }
 
-void *ccw_device_get_chp_desc(struct ccw_device *cdev, int chp_no)
+/**
+ * chp_get_chp_desc - return newly allocated channel-path descriptor
+ * @cdev: device to obtain the descriptor for
+ * @chp_idx: index of the channel path
+ *
+ * On success return a newly allocated copy of the channel-path description
+ * data associated with the given channel path. Return %NULL on error.
+ */
+struct channel_path_desc *ccw_device_get_chp_desc(struct ccw_device *cdev,
+						  int chp_idx)
 {
 	struct subchannel *sch;
 	struct chp_id chpid;
 
 	sch = to_subchannel(cdev->dev.parent);
 	chp_id_init(&chpid);
-	chpid.id = sch->schib.pmcw.chpid[chp_no];
+	chpid.id = sch->schib.pmcw.chpid[chp_idx];
 	return chp_get_chp_desc(chpid);
 }
 
@@ -704,9 +713,9 @@ EXPORT_SYMBOL(ccw_device_tm_start_timeout);
 int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
 {
 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
-	struct channel_path_desc_fmt1 desc;
+	struct channel_path *chp;
 	struct chp_id chpid;
-	int mdc = 0, ret, i;
+	int mdc = 0, i;
 
 	/* Adjust requested path mask to excluded varied off paths. */
 	if (mask)
@@ -719,14 +728,20 @@ int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
 		if (!(mask & (0x80 >> i)))
 			continue;
 		chpid.id = sch->schib.pmcw.chpid[i];
-		ret = chsc_determine_fmt1_channel_path_desc(chpid, &desc);
-		if (ret)
-			return ret;
-		if (!desc.f)
+		chp = chpid_to_chp(chpid);
+		if (!chp)
+			continue;
+
+		mutex_lock(&chp->lock);
+		if (!chp->desc_fmt1.f) {
+			mutex_unlock(&chp->lock);
 			return 0;
-		if (!desc.r)
+		}
+		if (!chp->desc_fmt1.r)
 			mdc = 1;
-		mdc = mdc ? min(mdc, (int)desc.mdc) : desc.mdc;
+		mdc = mdc ? min_t(int, mdc, chp->desc_fmt1.mdc) :
+			    chp->desc_fmt1.mdc;
+		mutex_unlock(&chp->lock);
 	}
 
 	return mdc;