net: dsa: remove master santiy check

Because we probe the master ourselves (and fail if there is no master),
it is not possible that we don't have a master device.

There is one catch though: device removal. We don't support that. It
wasn't supported neither before this patch. Because the master device
was only set in .pre_probe(), if a device was removed master_dev was a
dangling pointer and transmitting a frame cause a panic. I don't see a
good solution without having some sort of notify machanism when a
udevice is removed.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc> [DSA unit tests]
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>

diff --git a/net/dsa-uclass.c b/net/dsa-uclass.c
index d453cc6..7ea1cb6 100644 (file)
--- a/net/dsa-uclass.c
+++ b/net/dsa-uclass.c
@@ -69,11 +69,6 @@ static int dsa_port_start(struct udevice *pdev)
        struct dsa_ops *ops = dsa_get_ops(dev);
        int err;
 
-       if (!master) {
-               dev_err(pdev, "DSA master Ethernet device not found!\n");
-               return -EINVAL;
-       }
-
        if (ops->port_enable) {
                struct dsa_port_pdata *port_pdata;
 
@@ -108,13 +103,7 @@ static void dsa_port_stop(struct udevice *pdev)
                ops->port_disable(dev, priv->cpu_port, NULL);
        }
 
-       /*
-        * stop master only if it's active, don't probe it otherwise.
-        * Under normal usage it would be active because we're using it, but
-        * during tear-down it may have been removed ahead of us.
-        */
-       if (master && device_active(master))
-               eth_get_ops(master)->stop(master);
+       eth_get_ops(master)->stop(master);
 }
 
 /*
@@ -133,9 +122,6 @@ static int dsa_port_send(struct udevice *pdev, void *packet, int length)
        struct dsa_port_pdata *port_pdata;
        int err;
 
-       if (!master)
-               return -EINVAL;
-
        if (length + head + tail > PKTSIZE_ALIGN)
                return -EINVAL;
 
@@ -165,9 +151,6 @@ static int dsa_port_recv(struct udevice *pdev, int flags, uchar **packetp)
        struct dsa_port_pdata *port_pdata;
        int length, port_index, err;
 
-       if (!master)
-               return -EINVAL;
-
        length = eth_get_ops(master)->recv(master, flags, packetp);
        if (length <= 0)
                return length;
@@ -201,9 +184,6 @@ static int dsa_port_free_pkt(struct udevice *pdev, uchar *packet, int length)
        struct udevice *master = dsa_get_master(dev);
        struct dsa_priv *priv;
 
-       if (!master)
-               return -EINVAL;
-
        priv = dev_get_uclass_priv(dev);
        if (eth_get_ops(master)->free_pkt) {
                /* return the original pointer and length to master Eth */
@@ -284,6 +264,9 @@ static int dsa_port_probe(struct udevice *pdev)
        /*
         * Probe the master device. We depend on the master device for proper
         * operation and we also need it for MAC inheritance below.
+        *
+        * TODO: we assume the master device is always there and doesn't get
+        * removed during runtime.
         */
        ret = device_probe(master);
        if (ret)