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Vladimir Oltean 724395f4dc net: dsa: tag_8021q: don't broadcast during setup/teardown
Currently, on my board with multiple sja1105 switches in disjoint trees
described in commit f66a6a69f9 ("net: dsa: permit cross-chip bridging
between all trees in the system"), rebooting the board triggers the
following benign warnings:

[   12.345566] sja1105 spi2.0: port 0 failed to notify tag_8021q VLAN 1088 deletion: -ENOENT
[   12.353804] sja1105 spi2.0: port 0 failed to notify tag_8021q VLAN 2112 deletion: -ENOENT
[   12.362019] sja1105 spi2.0: port 1 failed to notify tag_8021q VLAN 1089 deletion: -ENOENT
[   12.370246] sja1105 spi2.0: port 1 failed to notify tag_8021q VLAN 2113 deletion: -ENOENT
[   12.378466] sja1105 spi2.0: port 2 failed to notify tag_8021q VLAN 1090 deletion: -ENOENT
[   12.386683] sja1105 spi2.0: port 2 failed to notify tag_8021q VLAN 2114 deletion: -ENOENT

Basically switch 1 calls dsa_tag_8021q_unregister, and switch 1's TX and
RX VLANs cannot be found on switch 2's CPU port.

But why would switch 2 even attempt to delete switch 1's TX and RX
tag_8021q VLANs from its CPU port? Well, because we use dsa_broadcast,
and it is supposed that it had added those VLANs in the first place
(because in dsa_port_tag_8021q_vlan_match, all CPU ports match
regardless of their tree index or switch index).

The two trees probe asynchronously, and when switch 1 probed, it called
dsa_broadcast which did not notify the tree of switch 2, because that
didn't probe yet. But during unbind, switch 2's tree _is_ probed, so it
_is_ notified of the deletion.

Before jumping to introduce a synchronization mechanism between the
probing across disjoint switch trees, let's take a step back and see
whether we _need_ to do that in the first place.

The RX and TX VLANs of switch 1 would be needed on switch 2's CPU port
only if switch 1 and 2 were part of a cross-chip bridge. And
dsa_tag_8021q_bridge_join takes care precisely of that (but if probing
was synchronous, the bridge_join would just end up bumping the VLANs'
refcount, because they are already installed by the setup path).

Since by the time the ports are bridged, all DSA trees are already set
up, and we don't need the tag_8021q VLANs of one switch installed on the
other switches during probe time, the answer is that we don't need to
fix the synchronization issue.

So make the setup and teardown code paths call dsa_port_notify, which
notifies only the local tree, and the bridge code paths call
dsa_broadcast, which let the other trees know as well.

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>
2021-08-12 11:46:21 +01:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-05 15:08:47 -07:00
block block-5.14-2021-07-30 2021-07-30 11:08:12 -07:00
certs Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-07-09 11:00:44 -07:00
Documentation devlink: Add new "enable_vnet" generic device param 2021-08-11 14:34:21 +01:00
drivers wwan: core: Unshadow error code returned by ida_alloc_range() 2021-08-12 10:55:07 +01:00
fs pipe: increase minimum default pipe size to 2 pages 2021-08-05 10:30:47 -07:00
include mctp: Specify route types, require rtm_type in RTM_*ROUTE messages 2021-08-11 16:01:17 -07:00
init xsurf100: drop include of lib8390.c 2021-08-03 13:05:26 +01:00
ipc Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
kernel Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-08-10 07:53:22 -07:00
lib bpf, tests: Add tail call test suite 2021-08-10 11:33:37 +02:00
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mm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-07-31 09:14:46 -07:00
net net: dsa: tag_8021q: don't broadcast during setup/teardown 2021-08-12 11:46:21 +01:00
samples samples, bpf: Add an explict comment to handle nested vlan tagging. 2021-08-10 11:17:32 +02:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-05 15:08:47 -07:00
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sound sound fixes for 5.14-rc3 2021-07-23 09:58:23 -07:00
tools Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-08-10 07:53:22 -07:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: Do not leak memory for duplicate debugfs directories 2021-08-04 06:02:03 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
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.mailmap m68k updates for v5.14 2021-06-28 14:01:03 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: move Murali Karicheri to credits 2021-04-29 15:47:30 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-07-31 09:14:46 -07:00
Makefile Various tracing fixes: 2021-08-05 11:53:34 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.