commit 36d04ba127eeed94b003155129c7509a2139b474
author Vivien Didelot <vivien.didelot@savoirfairelinux.com> Thu Oct 22 09:34:39 2015 -0400
committer David S. Miller <davem@davemloft.net> Thu Oct 22 07:38:37 2015 -0700
tree e416038fc106ced0086693a515bec1c2c04e36fa
parent ea70ba980666cffacb57d90d867b2c7952d90700

net: dsa: mv88e6xxx: write VID outside of VTU Get Next code

There is no need to write the VLAN ID before every Get Next operation,
since the VTU VID register is not cleared between calls.

Move the VID write call in a _mv88e6xxx_vtu_vid_write function outside
of _mv88e6xxx_vtu_getnext so future code could call VTU Get Next
multiple times and save a few register accesses.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx.c

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index 4591240..4b6baa6 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -1259,7 +1259,13 @@
 	return 0;
 }
 
-static int _mv88e6xxx_vtu_getnext(struct dsa_switch *ds, u16 vid,
+static int _mv88e6xxx_vtu_vid_write(struct dsa_switch *ds, u16 vid)
+{
+	return _mv88e6xxx_reg_write(ds, REG_GLOBAL, GLOBAL_VTU_VID,
+				    vid & GLOBAL_VTU_VID_MASK);
+}
+
+static int _mv88e6xxx_vtu_getnext(struct dsa_switch *ds,
 				  struct mv88e6xxx_vtu_stu_entry *entry)
 {
 	struct mv88e6xxx_vtu_stu_entry next = { 0 };
@@ -1269,11 +1275,6 @@
 	if (ret < 0)
 		return ret;
 
-	ret = _mv88e6xxx_reg_write(ds, REG_GLOBAL, GLOBAL_VTU_VID,
-				   vid & GLOBAL_VTU_VID_MASK);
-	if (ret < 0)
-		return ret;
-
 	ret = _mv88e6xxx_vtu_cmd(ds, GLOBAL_VTU_OP_VTU_GET_NEXT);
 	if (ret < 0)
 		return ret;
@@ -1485,7 +1486,12 @@
 	int err;
 
 	mutex_lock(&ps->smi_mutex);
-	err = _mv88e6xxx_vtu_getnext(ds, vid - 1, &vlan);
+
+	err = _mv88e6xxx_vtu_vid_write(ds, vid - 1);
+	if (err)
+		goto unlock;
+
+	err = _mv88e6xxx_vtu_getnext(ds, &vlan);
 	if (err)
 		goto unlock;
 
@@ -1514,7 +1520,11 @@
 
 	mutex_lock(&ps->smi_mutex);
 
-	err = _mv88e6xxx_vtu_getnext(ds, vid - 1, &vlan);
+	err = _mv88e6xxx_vtu_vid_write(ds, vid - 1);
+	if (err)
+		goto unlock;
+
+	err = _mv88e6xxx_vtu_getnext(ds, &vlan);
 	if (err)
 		goto unlock;
 
@@ -1558,7 +1568,11 @@
 		if (vid == 4095)
 			return -ENOENT;
 
-		err = _mv88e6xxx_vtu_getnext(ds, vid, entry);
+		err = _mv88e6xxx_vtu_vid_write(ds, vid);
+		if (err)
+			return err;
+
+		err = _mv88e6xxx_vtu_getnext(ds, entry);
 		if (err)
 			return err;
 
@@ -1584,7 +1598,12 @@
 		return -ENOENT;
 
 	mutex_lock(&ps->smi_mutex);
-	err = _mv88e6xxx_vtu_getnext(ds, *vid, &next);
+	err = _mv88e6xxx_vtu_vid_write(ds, *vid);
+	if (err)
+		goto unlock;
+
+	err = _mv88e6xxx_vtu_getnext(ds, &next);
+unlock:
 	mutex_unlock(&ps->smi_mutex);
 
 	if (err)