From: Vladimir Oltean <olteanv@gmail.com>
To: davem@davemloft.net
Cc: andrew@lunn.ch, f.fainelli@gmail.com, vivien.didelot@gmail.com,
madalin.bucur@oss.nxp.com, netdev@vger.kernel.org
Subject: [PATCH] dpaa_eth: fix usage as DSA master, try 3
Date: Mon, 25 May 2020 00:22:51 +0300 [thread overview]
Message-ID: <20200524212251.3311546-1-olteanv@gmail.com> (raw)
From: Vladimir Oltean <vladimir.oltean@nxp.com>
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-send-email-madalin.bucur@nxp.com/
(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>
---
drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index 2cd1f8efdfa3..6bfa7575af94 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -2914,7 +2914,7 @@ static int dpaa_eth_probe(struct platform_device *pdev)
}
/* 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);
--
2.25.1
next reply other threads:[~2020-05-24 21:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-24 21:22 Vladimir Oltean [this message]
2020-05-25 15:20 ` [PATCH] dpaa_eth: fix usage as DSA master, try 3 Madalin Bucur (OSS)
2020-05-25 15:36 ` Andrew Lunn
2020-05-25 16:14 ` Vladimir Oltean
2020-05-25 20:12 ` Florian Fainelli
2020-05-26 0:58 ` David Miller
2020-06-16 13:00 ` Vladimir Oltean
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