Commit Graph

18 Commits

Author SHA1 Message Date
Jakub Kicinski
5e655aadda Merge tag 'linux-can-fixes-for-6.18-20251014' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says:

====================
pull-request: can 2025-10-14

The first 2 paches are by Celeste Liu and target the gS_usb driver.
The first patch remove the limitation to 3 CAN interface per USB
device. The second patch adds the missing population of
net_device->dev_port.

The next 4 patches are by me and fix the m_can driver. They add a
missing pm_runtime_disable(), fix the CAN state transition back to
Error Active and fix the state after ifup and suspend/resume.

Another patch by me targets the m_can driver, too and replaces Dong
Aisheng's old email address.

The next 2 patches are by Vincent Mailhol and update the CAN
networking Documentation.

Tetsuo Handa contributes the last patch that add missing cleanup calls
in the NETDEV_UNREGISTER notification handler.

* tag 'linux-can-fixes-for-6.18-20251014' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  can: j1939: add missing calls in NETDEV_UNREGISTER notification handler
  can: add Transmitter Delay Compensation (TDC) documentation
  can: remove false statement about 1:1 mapping between DLC and length
  can: m_can: replace Dong Aisheng's old email address
  can: m_can: fix CAN state in system PM
  can: m_can: m_can_chip_config(): bring up interface in correct state
  can: m_can: m_can_handle_state_errors(): fix CAN state transition to Error Active
  can: m_can: m_can_plat_remove(): add missing pm_runtime_disable()
  can: gs_usb: gs_make_candev(): populate net_device->dev_port
  can: gs_usb: increase max interface to U8_MAX
====================

Link: https://patch.msgid.link/20251014122140.990472-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-15 17:56:20 -07:00
Vincent Mailhol
b5746b3e8e can: add Transmitter Delay Compensation (TDC) documentation
Back in 2021, support for CAN TDC was added to the kernel in series [1]
and in iproute2 in series [2]. However, the documentation was never
updated.

Add a new sub-section under CAN-FD driver support to document how to
configure the TDC using the "ip tool".

[1] add the netlink interface for CAN-FD Transmitter Delay Compensation (TDC)
Link: https://lore.kernel.org/all/20210918095637.20108-1-mailhol.vincent@wanadoo.fr/

[2] iplink_can: cleaning, fixes and adding TDC support
Link: https://lore.kernel.org/all/20211103164428.692722-1-mailhol.vincent@wanadoo.fr/

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20251013-can-fd-doc-v2-2-5d53bdc8f2ad@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-10-13 21:26:01 +02:00
Vincent Mailhol
c282993ccd can: remove false statement about 1:1 mapping between DLC and length
The CAN-FD section of can.rst still states that there is a 1:1 mapping
between the Classical CAN DLC and its length. This is only true for
the DLC values up to 8. Beyond that point, the length remains at 8.

For reference, the mapping between the CAN DLC and the length is given
in below table [1]:

	 DLC value	CBFF and CEFF	FBFF and FEFF
	 [decimal]	    [byte]	    [byte]
	----------------------------------------------
		 0		 0		 0
		 1		 1		 1
		 2		 2		 2
		 3		 3		 3
		 4		 4		 4
		 5		 5		 5
		 6		 6		 6
		 7		 7		 7
		 8		 8		 8
		 9		 8		12
		10		 8		16
		11		 8		20
		12		 8		24
		13		 8		32
		14		 8		48
		15		 8		64

Remove the erroneous statement. Instead just state that the length of
a Classical CAN frame ranges from 0 to 8.

[1] ISO 11898-1:2024, Table 5 -- DLC: coding of the four LSB

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20251013-can-fd-doc-v2-1-5d53bdc8f2ad@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-10-13 21:26:01 +02:00
Linus Torvalds
ee2fe81cdc Merge tag 'docs-6.18' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "It has been a relatively busy cycle in docsland, with changes all
  over:

   - Bring the kernel memory-model docs into the Sphinx build in the
     "literal include" mode.

   - Lots of build-infrastructure work, further cleaning up long-term
     kernel-doc technical debt. The sphinx-pre-install tool has been
     converted to Python and updated for current systems.

   - A new tool to detect when documents have been moved and generate
     HTML redirects; this can be used on kernel.org (or any other site
     hosting the rendered docs) to avoid breaking links.

   - Automated processing of the YAML files describing the netlink
     protocol.

   - A significant update of the maintainer's PGP guide.

  ... and a seemingly endless series of typo fixes, build-problem fixes,
  etc"

* tag 'docs-6.18' of git://git.lwn.net/linux: (193 commits)
  Documentation/features: Update feature lists for 6.17-rc7
  docs: remove cdomain.py
  Documentation/process: submitting-patches: fix typo in "were do"
  docs: dev-tools/lkmm: Fix typo of missing file extension
  Documentation: trace: histogram: Convert ftrace docs cross-reference
  Documentation: trace: histogram-design: Wrap introductory note in note:: directive
  Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram
  Documentation: trace: histogram-design: Trim trailing vertices in diagram explanation text
  Documentation: trace: histogram: Fix histogram trigger subsection number order
  docs: driver-api: fix spelling of "buses".
  Documentation: fbcon: Use admonition directives
  Documentation: fbcon: Reindent 8th step of attach/detach/unload
  Documentation: fbcon: Add boot options and attach/detach/unload section headings
  docs: filesystems: sysfs: add remaining top level sysfs directory descriptions
  docs: filesystems: sysfs: clarify symlink destinations in dev and bus/devices descriptions
  docs: filesystems: sysfs: remove top level sysfs net directory
  docs: maintainer: Fix ambiguous subheading formatting
  docs: kdoc: a few more dump_typedef() tweaks
  docs: kdoc: remove redundant comment stripping in dump_typedef()
  docs: kdoc: remove some dead code in dump_typedef()
  ...
2025-10-03 17:16:13 -07:00
Alex Tran
641427d5bf docs: networking: can: change bcm_msg_head frames member to support flexible array
The documentation of the 'bcm_msg_head' struct does not match how
it is defined in 'bcm.h'. Changed the frames member to a flexible array,
matching the definition in the header file.

See commit 94dfc73e7c ("treewide: uapi: Replace zero-length arrays with
flexible-array members")

Signed-off-by: Alex Tran <alex.t.tran@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20250904031709.1426895-1-alex.t.tran@gmail.com
Fixes: 94dfc73e7c ("treewide: uapi: Replace zero-length arrays with flexible-array members")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217783
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-09-09 14:12:38 +02:00
Bjorn Helgaas
e855d7e5e2 Documentation: Fix networking typos
Fix typos.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250813200526.290420-7-helgaas@kernel.org
2025-08-18 10:31:20 -06:00
Geert Uytterhoeven
9e97db3c07 documentation: networking: can: Document alloc_candev_mqs()
Since the introduction of alloc_candev_mqs() and friends, there is no
longer a need to allocate a generic network device and perform explicit
CAN-specific setup.  Remove the code showing this setup, and document
alloc_candev_mqs() instead.

Fixes: 39549eef35 ("can: CAN Network device driver and Netlink interface")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/c0f9a706ba31f1a49eb72e58526cd294d97a1ce9.1748865431.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2025-06-10 10:20:11 +02:00
Khaled Elnaggar
cde5959913 documentation: networking: fix spelling mistakes
Fix a couple of typos/spelling mistakes in the documentation.

Signed-off-by: Khaled Elnaggar <khaledelnaggarlinux@gmail.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://patch.msgid.link/20250123082521.59997-1-khaledelnaggarlinux@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-27 14:26:06 -08:00
Nicolas Maier
fec846fa7e can: bcm: add recvmsg flags for own, local and remote traffic
CAN RAW sockets allow userspace to tell if a received CAN frame comes
from the same socket, another socket on the same host, or another host.
See commit 1e55659ce6 ("can-raw: add msg_flags to distinguish local
traffic"). However, this feature is missing in CAN BCM sockets.

Add the same feature to CAN BCM sockets. When reading a received frame
(opcode RX_CHANGED) using recvmsg, two flags in msg->msg_flags may be
set following the previous convention (from CAN RAW), to distinguish
between 'own', 'local' and 'remote' CAN traffic.

Update the documentation to reflect this change.

Signed-off-by: Nicolas Maier <nicolas.maier.dev@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20240120081018.2319-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2024-02-12 16:55:17 +01:00
Randy Dunlap
a266ef69b8 Documentation: networking: correct spelling
Correct spelling problems for Documentation/networking/ as reported
by codespell.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Jiri Pirko <jiri@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20230129231053.20863-5-rdunlap@infradead.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-01-31 13:00:47 +01:00
Daniel S. Trevitz
85700ac19a can: add termination resistor documentation
Add documentation for how to use and setup the switchable termination
resistor support for CAN controllers.

Signed-off-by: Daniel Trevitz <dan@sstrev.com>
Link: https://lore.kernel.org/all/3441354.44csPzL39Z@daniel6430
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-10-19 21:33:29 +02:00
Max Staudt
a9cf02c6a6 can: Break loopback loop on loopback documentation
There are two sections called "Local Loopback of Sent Frames". One was
meant to link to the other, but pointed at itself instead.

Link: https://lore.kernel.org/all/20220611171155.9090-1-max@enpas.org
Fixes: 7d59773945 ("can: migrate documentation to restructured text")
Signed-off-by: Max Staudt <max@enpas.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11 22:40:13 +02:00
Erik Flodin
924e464f4a can: add a note that RECV_OWN_MSGS frames are subject to filtering
Some parts of the documentation may lead the reader to think that the
socket's own frames are always received when CAN_RAW_RECV_OWN_MSGS is
enabled, but all frames are subject to filtering.

As explained by Marc Kleine-Budde:

On TX complete of a CAN frame it's pushed into the RX path of the
networking stack, along with the information of the originating socket.

Then the CAN frame is delivered into AF_CAN, where it is passed on to
all registered receivers depending on filters. One receiver is the
sending socket in CAN_RAW. Then in CAN_RAW the it is checked if the
sending socket has RECV_OWN_MSGS enabled.

Link: https://lore.kernel.org/r/20210420191212.42753-1-erik@flodin.me
Signed-off-by: Erik Flodin <erik@flodin.me>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-04-24 14:36:51 +02:00
Oliver Hartkopp
75191707c7 can: update documentation for DLC usage in Classical CAN
The extension of struct can_frame with the len8_dlc element and the
can_dlc naming issue required an update of the documentation.

Additionally introduce the term 'Classical CAN' which has been established
by CAN in Automation to separate the original CAN2.0 A/B from CAN FD.

Updated some data structures and flags.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-7-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20 12:05:14 +01:00
Oliver Hartkopp
3ab4ce0d6f can: rename CAN FD related can_len2dlc and can_dlc2len helpers
The helper functions can_len2dlc and can_dlc2len are only relevant for
CAN FD data length code (DLC) conversion.

To fit the introduced can_cc_dlc2len for Classical CAN we rename:

can_dlc2len -> can_fd_dlc2len to get the payload length from the DLC
can_len2dlc -> can_fd_len2dlc to get the DLC from the payload length

Suggested-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-6-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-11-20 12:05:14 +01:00
Mauro Carvalho Chehab
482a4360c5 docs: networking: convert netdevices.txt to ReST
- add SPDX header;
- adjust title markup;
- mark lists as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:56:36 -07:00
Mauro Carvalho Chehab
b701745097 docs: can.rst: fix a footnote reference
As stated at:
	http://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html#footnotes

A footnote should contain either a number, a reference or
an auto number, e. g.:
        [1], [#f1] or [#].

While using [*] accidentaly works for html, it fails for other
document outputs. In particular, it causes an error with LaTeX
output, causing all books after networking to not be built.

So, replace it by a valid syntax.

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-15 12:48:59 -03:00
Robert Schwebel
7d59773945 can: migrate documentation to restructured text
The kernel documentation is now restructured text. Convert the SocketCAN
documentation and include it in the toplevel kernel documentation.

This patch doesn't do any content change.

All references to can.txt in the code are converted to can.rst.

Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-01-26 10:46:44 +01:00