From: Lukas Wunner lukas@wunner.de
[ Upstream commit 9624bafa5f6418b9ca5b3f66d1f6a6a2e8bf6d4c ]
The ks8851 chip's initial carrier state is down. A Link Change Interrupt is signaled once interrupts are enabled if the carrier is up.
The ks8851 driver has it backwards by assuming that the initial carrier state is up. The state is therefore misrepresented if the interface is opened with no cable attached. Fix it.
The Link Change interrupt is sometimes not signaled unless the P1MBSR register (which contains the Link Status bit) is read on ->ndo_open(). This might be a hardware erratum. Read the register by calling mii_check_link(), which has the desirable side effect of setting the carrier state to down if the cable was detached while the interface was closed.
Signed-off-by: Lukas Wunner lukas@wunner.de Cc: Frank Pavlic f.pavlic@kunbus.de Cc: Ben Dooks ben.dooks@codethink.co.uk Cc: Tristram Ha Tristram.Ha@microchip.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin (Microsoft) sashal@kernel.org --- drivers/net/ethernet/micrel/ks8851.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c index c9faec4c5b25..b83b070a9eec 100644 --- a/drivers/net/ethernet/micrel/ks8851.c +++ b/drivers/net/ethernet/micrel/ks8851.c @@ -858,6 +858,7 @@ static int ks8851_net_open(struct net_device *dev) netif_dbg(ks, ifup, ks->netdev, "network device up\n");
mutex_unlock(&ks->lock); + mii_check_link(&ks->mii); return 0; }
@@ -1519,6 +1520,7 @@ static int ks8851_probe(struct spi_device *spi)
spi_set_drvdata(spi, ks);
+ netif_carrier_off(ks->netdev); ndev->if_port = IF_PORT_100BASET; ndev->netdev_ops = &ks8851_netdev_ops; ndev->irq = spi->irq;