Commit Graph

907 Commits

Author SHA1 Message Date
Miaoqian Lin
72ae15d5ce net: dsa: Add missing of_node_put() in dsa_port_link_register_of
[ Upstream commit fc06b2867f ]

The device_node pointer is returned by of_parse_phandle()  with refcount
incremented. We should use of_node_put() on it when done.
of_node_put() will check for NULL value.

Fixes: a20f997010 ("net: dsa: Don't instantiate phylink for CPU/DSA ports unless needed")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-09 09:05:02 +02:00
Miaoqian Lin
ba50073cf4 net: dsa: Add missing of_node_put() in dsa_port_parse_of
[ Upstream commit cb0b430b4e ]

The device_node pointer is returned by of_parse_phandle()  with refcount
incremented. We should use of_node_put() on it when done.

Fixes: 6d4e5c570c ("net: dsa: get port type at parse time")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220316082602.10785-1-linmq006@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-23 09:13:28 +01:00
Vladimir Oltean
43c880b860 net: dsa: don't allocate the slave_mii_bus using devres
[ Upstream commit 5135e96a3d ]

The Linux device model permits both the ->shutdown and ->remove driver
methods to get called during a shutdown procedure. Example: a DSA switch
which sits on an SPI bus, and the SPI bus driver calls this on its
->shutdown method:

spi_unregister_controller
-> device_for_each_child(&ctlr->dev, NULL, __unregister);
   -> spi_unregister_device(to_spi_device(dev));
      -> device_del(&spi->dev);

So this is a simple pattern which can theoretically appear on any bus,
although the only other buses on which I've been able to find it are
I2C:

i2c_del_adapter
-> device_for_each_child(&adap->dev, NULL, __unregister_client);
   -> i2c_unregister_device(client);
      -> device_unregister(&client->dev);

The implication of this pattern is that devices on these buses can be
unregistered after having been shut down. The drivers for these devices
might choose to return early either from ->remove or ->shutdown if the
other callback has already run once, and they might choose that the
->shutdown method should only perform a subset of the teardown done by
->remove (to avoid unnecessary delays when rebooting).

So in other words, the device driver may choose on ->remove to not
do anything (therefore to not unregister an MDIO bus it has registered
on ->probe), because this ->remove is actually triggered by the
device_shutdown path, and its ->shutdown method has already run and done
the minimally required cleanup.

This used to be fine until the blamed commit, but now, the following
BUG_ON triggers:

void mdiobus_free(struct mii_bus *bus)
{
	/* For compatibility with error handling in drivers. */
	if (bus->state == MDIOBUS_ALLOCATED) {
		kfree(bus);
		return;
	}

	BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
	bus->state = MDIOBUS_RELEASED;

	put_device(&bus->dev);
}

In other words, there is an attempt to free an MDIO bus which was not
unregistered. The attempt to free it comes from the devres release
callbacks of the SPI device, which are executed after the device is
unregistered.

I'm not saying that the fact that MDIO buses allocated using devres
would automatically get unregistered wasn't strange. I'm just saying
that the commit didn't care about auditing existing call paths in the
kernel, and now, the following code sequences are potentially buggy:

(a) devm_mdiobus_alloc followed by plain mdiobus_register, for a device
    located on a bus that unregisters its children on shutdown. After
    the blamed patch, either both the alloc and the register should use
    devres, or none should.

(b) devm_mdiobus_alloc followed by plain mdiobus_register, and then no
    mdiobus_unregister at all in the remove path. After the blamed
    patch, nobody unregisters the MDIO bus anymore, so this is even more
    buggy than the previous case which needs a specific bus
    configuration to be seen, this one is an unconditional bug.

In this case, DSA falls into category (a), it tries to be helpful and
registers an MDIO bus on behalf of the switch, which might be on such a
bus. I've no idea why it does it under devres.

It does this on probe:

	if (!ds->slave_mii_bus && ds->ops->phy_read)
		alloc and register mdio bus

and this on remove:

	if (ds->slave_mii_bus && ds->ops->phy_read)
		unregister mdio bus

I _could_ imagine using devres because the condition used on remove is
different than the condition used on probe. So strictly speaking, DSA
cannot determine whether the ds->slave_mii_bus it sees on remove is the
ds->slave_mii_bus that _it_ has allocated on probe. Using devres would
have solved that problem. But nonetheless, the existing code already
proceeds to unregister the MDIO bus, even though it might be
unregistering an MDIO bus it has never registered. So I can only guess
that no driver that implements ds->ops->phy_read also allocates and
registers ds->slave_mii_bus itself.

So in that case, if unregistering is fine, freeing must be fine too.

Stop using devres and free the MDIO bus manually. This will make devres
stop attempting to free a still registered MDIO bus on ->shutdown.

Fixes: ac3a68d566 ("net: phy: don't abuse devres in devm_mdiobus_register()")
Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30 10:11:02 +02:00
Linus Walleij
5711ced58e net: dsa: tag_rtl4_a: Fix egress tags
[ Upstream commit 0e90dfa7a8 ]

I noticed that only port 0 worked on the RTL8366RB since we
started to use custom tags.

It turns out that the format of egress custom tags is actually
different from ingress custom tags. While the lower bits just
contain the port number in ingress tags, egress tags need to
indicate destination port by setting the bit for the
corresponding port.

It was working on port 0 because port 0 added 0x00 as port
number in the lower bits, and if you do this the packet appears
at all ports, including the intended port. Ooops.

Fix this and all ports work again. Use the define for shifting
the "type A" into place while we're at it.

Tested on the D-Link DIR-685 by sending traffic to each of
the ports in turn. It works.

Fixes: 86dd9868b8 ("net: dsa: tag_rtl4_a: Support also egress tags")
Cc: DENG Qingfang <dqfext@gmail.com>
Cc: Mauri Sandberg <sandberg@mailfence.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 12:28:04 +02:00
Vladimir Oltean
cf6f29bb2c net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup
commit 6a52e73368 upstream.

DSA supports connecting to a phy-handle, and has a fallback to a non-OF
based method of connecting to an internal PHY on the switch's own MDIO
bus, if no phy-handle and no fixed-link nodes were present.

The -ENODEV error code from the first attempt (phylink_of_phy_connect)
is what triggers the second attempt (phylink_connect_phy).

However, when the first attempt returns a different error code than
-ENODEV, this results in an unbalance of calls to phylink_create and
phylink_destroy by the time we exit the function. The phylink instance
has leaked.

There are many other error codes that can be returned by
phylink_of_phy_connect. For example, phylink_validate returns -EINVAL.
So this is a practical issue too.

Fixes: aab9c4067d ("net: dsa: Plug in PHYLINK support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20210914134331.2303380-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 12:27:58 +02:00
Vladimir Oltean
66c73f187d net: dsa: properly check for the bridge_leave methods in dsa_switch_bridge_leave()
commit bcb9928a15 upstream.

This was not caught because there is no switch driver which implements
the .port_bridge_join but not .port_bridge_leave method, but it should
nonetheless be fixed, as in certain conditions (driver development) it
might lead to NULL pointer dereference.

Fixes: f66a6a69f9 ("net: dsa: permit cross-chip bridging between all trees in the system")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:36:20 +02:00
Vladimir Oltean
09fdb6747b net: dsa: tag_8021q: fix the VLAN IDs used for encoding sub-VLANs
[ Upstream commit 4ef8d857b5 ]

When using sub-VLANs in the range of 1-7, the resulting value from:

	rx_vid = dsa_8021q_rx_vid_subvlan(ds, port, subvlan);

is wrong according to the description from tag_8021q.c:

 | 11  | 10  |  9  |  8  |  7  |  6  |  5  |  4  |  3  |  2  |  1  |  0  |
 +-----------+-----+-----------------+-----------+-----------------------+
 |    DIR    | SVL |    SWITCH_ID    |  SUBVLAN  |          PORT         |
 +-----------+-----+-----------------+-----------+-----------------------+

For example, when ds->index == 0, port == 3 and subvlan == 1,
dsa_8021q_rx_vid_subvlan() returns 1027, same as it returns for
subvlan == 0, but it should have returned 1043.

This is because the low portion of the subvlan bits are not masked
properly when writing into the 12-bit VLAN value. They are masked into
bits 4:3, but they should be masked into bits 5:4.

Fixes: 3eaae1d05f ("net: dsa: tag_8021q: support up to 8 VLANs per port using sub-VLANs")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10 13:39:17 +02:00
Vladimir Oltean
d7932e6852 net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count
[ Upstream commit b94cbc909f ]

DSA implements a bunch of 'standardized' ethtool statistics counters,
namely tx_packets, tx_bytes, rx_packets, rx_bytes. So whatever the
hardware driver returns in .get_sset_count(), we need to add 4 to that.

That is ok, except that .get_sset_count() can return a negative error
code, for example:

b53_get_sset_count
-> phy_ethtool_get_sset_count
   -> return -EIO

-EIO is -5, and with 4 added to it, it becomes -1, aka -EPERM. One can
imagine that certain error codes may even become positive, although
based on code inspection I did not see instances of that.

Check the error code first, if it is negative return it as-is.

Based on a similar patch for dsa_master_get_strings from Dan Carpenter:
https://patchwork.kernel.org/project/netdevbpf/patch/YJaSe3RPgn7gKxZv@mwanda/

Fixes: 91da11f870 ("net: Distributed Switch Architecture protocol support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03 09:00:45 +02:00
Dan Carpenter
caff86f855 net: dsa: fix a crash if ->get_sset_count() fails
commit a269333fa5 upstream.

If ds->ops->get_sset_count() fails then it "count" is a negative error
code such as -EOPNOTSUPP.  Because "i" is an unsigned int, the negative
error code is type promoted to a very high value and the loop will
corrupt memory until the system crashes.

Fix this by checking for error codes and changing the type of "i" to
just int.

Fixes: badf3ada60 ("net: dsa: Provide CPU port statistics to master netdev")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 09:00:38 +02:00
Maxim Kochetkov
63a64c366c net: dsa: Fix type was not set for devlink port
[ Upstream commit fb6ec87f72 ]

If PHY is not available on DSA port (described at devicetree but absent or
failed to detect) then kernel prints warning after 3700 secs:

[ 3707.948771] ------------[ cut here ]------------
[ 3707.948784] Type was not set for devlink port.
[ 3707.948894] WARNING: CPU: 1 PID: 17 at net/core/devlink.c:8097 0xc083f9d8

We should unregister the devlink port as a user port and
re-register it as an unused port before executing "continue" in case of
dsa_port_setup error.

Fixes: 86f8b1c01a ("net: dsa: Do not make user port errors fatal")
Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14 08:42:07 +02:00
DENG Qingfang
606cfdeebd net: dsa: tag_mtk: fix 802.1ad VLAN egress
[ Upstream commit 9200f515c4 ]

A different TPID bit is used for 802.1ad VLAN frames.

Reported-by: Ilario Gelmetti <iochesonome@gmail.com>
Fixes: f0af34317f ("net: dsa: mediatek: combine MediaTek tag with VLAN tag")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:22 +01:00
Vladimir Oltean
409af89466 net: dsa: tag_ar9331: let DSA core deal with TX reallocation
[ Upstream commit 86c4ad9a78 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Cc: Per Forlin <per.forlin@axis.com>
Cc: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Oleksij Rempel <linux@rempel-privat.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:22 +01:00
Vladimir Oltean
a2fd181b4b net: dsa: tag_gswip: let DSA core deal with TX reallocation
[ Upstream commit 9b9826ae11 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

This one is interesting, the DSA tag is 8 bytes on RX and 4 bytes on TX.
Because DSA is unaware of asymmetrical tag lengths, the overhead/needed
headroom is declared as 8 bytes and therefore 4 bytes larger than it
needs to be. If this becomes a problem, and the GSWIP driver can't be
converted to a uniform header length, we might need to make DSA aware of
separate RX/TX overhead values.

Cc: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:22 +01:00
Vladimir Oltean
9bb1bec952 net: dsa: tag_dsa: let DSA core deal with TX reallocation
[ Upstream commit 952a063450 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Similar to the EtherType DSA tagger, the old Marvell tagger can
transform an 802.1Q header if present into a DSA tag, so there is no
headroom required in that case. But we are ensuring that it exists,
regardless (practically speaking, the headroom must be 4 bytes larger
than it needs to be).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
9ad635b75e net: dsa: tag_brcm: let DSA core deal with TX reallocation
[ Upstream commit 2f0d030c5f ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
67fd35c21a net: dsa: tag_edsa: let DSA core deal with TX reallocation
[ Upstream commit c6c4e1237d ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Note that the VLAN code path needs a smaller extra headroom than the
regular EtherType DSA path. That isn't a problem, because this tagger
declares the larger tag length (8 bytes vs 4) as the protocol overhead,
so we are covered in both cases.

Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
6702dd4553 net: dsa: tag_lan9303: let DSA core deal with TX reallocation
[ Upstream commit 6ed94135f5 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
27f014eb66 net: dsa: tag_mtk: let DSA core deal with TX reallocation
[ Upstream commit 941f66beb7 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Cc: DENG Qingfang <dqfext@gmail.com>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: John Crispin <john@phrozen.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
54787024c8 net: dsa: tag_ocelot: let DSA core deal with TX reallocation
[ Upstream commit 9c5c3bd005 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
cf5c6682e2 net: dsa: tag_qca: let DSA core deal with TX reallocation
[ Upstream commit 9bbda29ae1 ]

Now that we have a central TX reallocation procedure that accounts for
the tagger's needed headroom in a generic way, we can remove the
skb_cow_head call.

Cc: John Crispin <john@phrozen.org>
Cc: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Christian Eggers
8f17133cc3 net: dsa: trailer: don't allocate additional memory for padding/tagging
[ Upstream commit ef3f72fee2 ]

The caller (dsa_slave_xmit) guarantees that the frame length is at least
ETH_ZLEN and that enough memory for tail tagging is available.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Christian Eggers
a4d2836de5 net: dsa: tag_ksz: don't allocate additional memory for padding/tagging
[ Upstream commit 88fda8eefd ]

The caller (dsa_slave_xmit) guarantees that the frame length is at least
ETH_ZLEN and that enough memory for tail tagging is available.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
Vladimir Oltean
162c423e60 net: dsa: implement a central TX reallocation procedure
[ Upstream commit a3b0b64797 ]

At the moment, taggers are left with the task of ensuring that the skb
headers are writable (which they aren't, if the frames were cloned for
TX timestamping, for flooding by the bridge, etc), and that there is
enough space in the skb data area for the DSA tag to be pushed.

Moreover, the life of tail taggers is even harder, because they need to
ensure that short frames have enough padding, a problem that normal
taggers don't have.

The principle of the DSA framework is that everything except for the
most intimate hardware specifics (like in this case, the actual packing
of the DSA tag bits) should be done inside the core, to avoid having
code paths that are very rarely tested.

So provide a TX reallocation procedure that should cover the known needs
of DSA today.

Note that this patch also gives the network stack a good hint about the
headroom/tailroom it's going to need. Up till now it wasn't doing that.
So the reallocation procedure should really be there only for the
exceptional cases, and for cloned packets which need to be unshared.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Christian Eggers <ceggers@arri.de> # For tail taggers only
Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:21 +01:00
DENG Qingfang
68277f69a8 net: dsa: tag_rtl4_a: fix egress tags
commit 9eb8bc593a upstream.

Commit 86dd9868b8 has several issues, but was accepted too soon
before anyone could take a look.

- Double free. dsa_slave_xmit() will free the skb if the xmit function
  returns NULL, but the skb is already freed by eth_skb_pad(). Use
  __skb_put_padto() to avoid that.
- Unnecessary allocation. It has been done by DSA core since commit
  a3b0b64797.
- A u16 pointer points to skb data. It should be __be16 for network
  byte order.
- Typo in comments. "numer" -> "number".

Fixes: 86dd9868b8 ("net: dsa: tag_rtl4_a: Support also egress tags")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:13 +01:00
Linus Walleij
10b55a0a7f net: dsa: tag_rtl4_a: Support also egress tags
commit 86dd9868b8 upstream.

Support also transmitting frames using the custom "8899 A"
4 byte tag.

Qingfang came up with the solution: we need to pad the
ethernet frame to 60 bytes using eth_skb_pad(), then the
switch will happily accept frames with custom tags.

Cc: Mauri Sandberg <sandberg@mailfence.com>
Reported-by: DENG Qingfang <dqfext@gmail.com>
Fixes: efd7fe68f0 ("net: dsa: tag_rtl4_a: Implement Realtek 4 byte A tag")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:34:07 +01:00