]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
net: dsa: lan9303: Do not disable switch fabric port 0 at .probe
authorEgil Hjelmeland <privat@egil-hjelmeland.no>
Tue, 24 Oct 2017 15:14:10 +0000 (17:14 +0200)
committerDavid S. Miller <davem@davemloft.net>
Thu, 26 Oct 2017 08:40:32 +0000 (17:40 +0900)
commit3c91b0c1de8d013490bbc41ce9ee8810ea5baddd
tree837720e8983191cdd9b9804988a3d26061c72cbb
parentacfdf7eabea4186a386ba5e656f0c739563cb1a5
net: dsa: lan9303: Do not disable switch fabric port 0 at .probe

Make the LAN9303 work when lan9303_probe() is called twice.

For some unknown reason the LAN9303 switch fail to forward data when switch
fabric port 0 TX is disabled during probe. (Write of LAN9303_MAC_TX_CFG_0
in lan9303_disable_processing_port().)

In that situation the switch fabric seem to receive frames, because the ALR
is learning addresses. But no frames are transmitted on any of the ports.

In our system lan9303_probe() is called twice, first time
dsa_register_switch() return -EPROBE_DEFER. As an experiment, modified the
code to skip writing LAN9303_MAC_TX_CFG_0, port 0 during the first probe.
Then the switch works as expected.

Resolve the problem by not calling lan9303_disable_processing_port() on
port 0 during probe. Ports 1 and 2 are still disabled.

Although unsatisfying that the exact failure mechanism is not known,
the patch should not cause any harm.

Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/dsa/lan9303-core.c