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e1b9e80236
There are 2 distinct code paths (listed below) in the source code which
set up an injection header for Ocelot(-like) switches. Code path (2)
lacks the QoS class and source port being set correctly. Especially the
improper QoS classification is a problem for the "ocelot-8021q"
alternative DSA tagging protocol, because we support tc-taprio and each
packet needs to be scheduled precisely through its time slot. This
includes PTP, which is normally assigned to a traffic class other than
0, but would be sent through TC 0 nonetheless.
The code paths are:
(1) ocelot_xmit_common() from net/dsa/tag_ocelot.c - called only by the
standard "ocelot" DSA tagging protocol which uses NPI-based
injection - sets up bit fields in the tag manually to account for
a small difference (destination port offset) between Ocelot and
Seville. Namely, ocelot_ifh_set_dest() is omitted out of
ocelot_xmit_common(), because there's also seville_ifh_set_dest().
(2) ocelot_ifh_set_basic(), called by:
- ocelot_fdma_prepare_skb() for FDMA transmission of the ocelot
switchdev driver
- ocelot_port_xmit() -> ocelot_port_inject_frame() for
register-based transmission of the ocelot switchdev driver
- felix_port_deferred_xmit() -> ocelot_port_inject_frame() for the
DSA tagger ocelot-8021q when it must transmit PTP frames (also
through register-based injection).
sets the bit fields according to its own logic.
The problem is that (2) doesn't call ocelot_ifh_set_qos_class().
Copying that logic from ocelot_xmit_common() fixes that.
Unfortunately, although desirable, it is not easily possible to
de-duplicate code paths (1) and (2), and make net/dsa/tag_ocelot.c
directly call ocelot_ifh_set_basic()), because of the ocelot/seville
difference. This is the "minimal" fix with some logic duplicated (but
at least more consolidated).
Fixes:
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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 reStructuredText 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.