net: dsa/mv88e6xxx: add reg read and write debug
This commit adds debug messages for the generic mv88e6xxx read and write
routines. The output is similar to this:
mdio-gpio mdio-gpio.0: <- addr: 0x1b reg: 0x05 val: 0x4000
mdio-gpio mdio-gpio.0: -> addr: 0x1b reg: 0x07 val: 0x3113
mdio-gpio mdio-gpio.0: -> addr: 0x1b reg: 0x08 val: 0x0330
mdio-gpio mdio-gpio.0: -> addr: 0x1b reg: 0x09 val: 0x0000
This is convenient to dynamically debug operations through debugfs with:
echo file mv88e6xxx.c +p > <debugfs>/dynamic_debug/control
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 cd6807c..3e7e31a 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -85,6 +85,12 @@
ret = __mv88e6xxx_reg_read(bus, ds->pd->sw_addr, addr, reg);
mutex_unlock(&ps->smi_mutex);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(ds->master_dev, "<- addr: 0x%.2x reg: 0x%.2x val: 0x%.4x\n",
+ addr, reg, ret);
+
return ret;
}
@@ -128,6 +134,9 @@
if (bus == NULL)
return -EINVAL;
+ dev_dbg(ds->master_dev, "-> addr: 0x%.2x reg: 0x%.2x val: 0x%.4x\n",
+ addr, reg, val);
+
mutex_lock(&ps->smi_mutex);
ret = __mv88e6xxx_reg_write(bus, ds->pd->sw_addr, addr, reg, val);
mutex_unlock(&ps->smi_mutex);