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 --- net/dsa-uclass.c | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-)
diff --git a/net/dsa-uclass.c b/net/dsa-uclass.c index d453cc6930..7ea1cb6949 100644 --- 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)