Commit 3c91b0c1 authored by Egil Hjelmeland's avatar Egil Hjelmeland Committed by David S. Miller

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: default avatarEgil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent acfdf7ea
...@@ -818,7 +818,7 @@ static int lan9303_disable_processing(struct lan9303 *chip) ...@@ -818,7 +818,7 @@ static int lan9303_disable_processing(struct lan9303 *chip)
{ {
int p; int p;
for (p = 0; p < LAN9303_NUM_PORTS; p++) { for (p = 1; p < LAN9303_NUM_PORTS; p++) {
int ret = lan9303_disable_processing_port(chip, p); int ret = lan9303_disable_processing_port(chip, p);
if (ret) if (ret)
......
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