net: dsa: mv88e6xxx: protect SID register access

Introduce a mv88e6xxx_has_stu() helper to protect the access to the
GLOBAL_VTU_SID register, instead of checking switch families.

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

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index 50454be..29b2444 100644 (file)
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -482,6 +482,16 @@ static bool mv88e6xxx_6352_family(struct dsa_switch *ds)
        return false;
 }
 
+static bool mv88e6xxx_has_stu(struct dsa_switch *ds)
+{
+       /* Does the device have STU and dedicated SID registers for VTU ops? */
+       if (mv88e6xxx_6097_family(ds) || mv88e6xxx_6165_family(ds) ||
+           mv88e6xxx_6351_family(ds) || mv88e6xxx_6352_family(ds))
+               return true;
+
+       return false;
+}
+
 /* We expect the switch to perform auto negotiation if there is a real
  * phy. However, in the case of a fixed link phy, we force the port
  * settings from the fixed link settings.
@@ -1329,7 +1339,9 @@ static int _mv88e6xxx_vtu_getnext(struct dsa_switch *ds,
                                return ret;
 
                        next.fid = ret & GLOBAL_VTU_FID_MASK;
+               }
 
+               if (mv88e6xxx_has_stu(ds)) {
                        ret = _mv88e6xxx_reg_read(ds, REG_GLOBAL,
                                                  GLOBAL_VTU_SID);
                        if (ret < 0)
@@ -1412,8 +1424,7 @@ static int _mv88e6xxx_vtu_loadpurge(struct dsa_switch *ds,
        if (ret < 0)
                return ret;
 
-       if (mv88e6xxx_6097_family(ds) || mv88e6xxx_6165_family(ds) ||
-           mv88e6xxx_6351_family(ds) || mv88e6xxx_6352_family(ds)) {
+       if (mv88e6xxx_has_stu(ds)) {
                reg = entry->sid & GLOBAL_VTU_SID_MASK;
                ret = _mv88e6xxx_reg_write(ds, REG_GLOBAL, GLOBAL_VTU_SID, reg);
                if (ret < 0)