From: Egil Hjelmeland privat@egil-hjelmeland.no
[ Upstream commit 3c91b0c1de8d013490bbc41ce9ee8810ea5baddd ]
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 Signed-off-by: Sasha Levin alexander.levin@verizon.com --- drivers/net/dsa/lan9303-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c index b471413d3df9..1e5a69b9d90a 100644 --- a/drivers/net/dsa/lan9303-core.c +++ b/drivers/net/dsa/lan9303-core.c @@ -569,7 +569,7 @@ static int lan9303_disable_processing(struct lan9303 *chip) { 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);
if (ret)