From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 5d14c304bfc14b4fd052dc83d5224376b48f52f0 ]
The dpaa-eth driver probes on compatible string for the MAC node, and the fman/mac.c driver allocates a dpaa-ethernet platform device that triggers the probing of the dpaa-eth net device driver.
All of this is fine, but the problem is that the struct device of the dpaa_eth net_device is 2 parents away from the MAC which can be referenced via of_node. So of_find_net_device_by_node can't find it, and DSA switches won't be able to probe on top of FMan ports.
It would be a bit silly to modify a core function (of_find_net_device_by_node) to look for dev->parent->parent->of_node just for one driver. We're just 1 step away from implementing full recursion.
Actually there have already been at least 2 previous attempts to make this work: - Commit a1a50c8e4c24 ("fsl/man: Inherit parent device and of_node") - One or more of the patches in "[v3,0/6] adapt DPAA drivers for DSA": https://patchwork.ozlabs.org/project/netdev/cover/1508178970-28945-1-git-sen... (I couldn't really figure out which one was supposed to solve the problem and how).
Point being, it looks like this is still pretty much a problem today. On T1040, the /sys/class/net/eth0 symlink currently points to
../../devices/platform/ffe000000.soc/ffe400000.fman/ffe4e6000.ethernet/dpaa-ethernet.0/net/eth0
which pretty much illustrates the problem. The closest of_node we've got is the "fsl,fman-memac" at /soc@ffe000000/fman@400000/ethernet@e6000, which is what we'd like to be able to reference from DSA as host port.
For of_find_net_device_by_node to find the eth0 port, we would need the parent of the eth0 net_device to not be the "dpaa-ethernet" platform device, but to point 1 level higher, aka the "fsl,fman-memac" node directly. The new sysfs path would look like this:
../../devices/platform/ffe000000.soc/ffe400000.fman/ffe4e6000.ethernet/net/eth0
And this is exactly what SET_NETDEV_DEV does. It sets the parent of the net_device. The new parent has an of_node associated with it, and of_dev_node_match already checks for the of_node of the device or of its parent.
Fixes: a1a50c8e4c24 ("fsl/man: Inherit parent device and of_node") Fixes: c6e26ea8c893 ("dpaa_eth: change device used") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c @@ -2802,7 +2802,7 @@ static int dpaa_eth_probe(struct platfor }
/* Do this here, so we can be verbose early */ - SET_NETDEV_DEV(net_dev, dev); + SET_NETDEV_DEV(net_dev, dev->parent); dev_set_drvdata(dev, net_dev);
priv = netdev_priv(net_dev);