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Introduce a method to calculate the exact size in bits of a CAN(-FD)
frame with or without dynamic bitstuffing.
These are all the possible combinations taken into account:
- Classical CAN or CAN-FD
- Standard or Extended frame format
- CAN-FD CRC17 or CRC21
- Include or not intermission
Instead of doing several individual macro definitions, declare the
can_frame_bits() function-like macro. To this extent, do a full
refactoring of the length definitions.
In addition add the can_frame_bytes(). This function-like macro
replaces the existing macro:
- CAN_FRAME_OVERHEAD_SFF: can_frame_bytes(false, false, 0)
- CAN_FRAME_OVERHEAD_EFF: can_frame_bytes(false, true, 0)
- CANFD_FRAME_OVERHEAD_SFF: can_frame_bytes(true, false, 0)
- CANFD_FRAME_OVERHEAD_EFF: can_frame_bytes(true, true, 0)
Function-like macros were chosen over inline functions because they
can be used to initialize const struct fields.
The different maximum frame lengths (maximum data length, including
intermission) are as follow:
Frame type bits bytes
-------------------------------------------------------
Classic CAN SFF no bitstuffing 111 14
Classic CAN EFF no bitstuffing 131 17
Classic CAN SFF bitstuffing 135 17
Classic CAN EFF bitstuffing 160 20
CAN-FD SFF no bitstuffing 579 73
CAN-FD EFF no bitstuffing 598 75
CAN-FD SFF bitstuffing 712 89
CAN-FD EFF bitstuffing 736 92
The macro CAN_FRAME_LEN_MAX and CANFD_FRAME_LEN_MAX are kept as an
alias to, respectively, can_frame_bytes(false, true, CAN_MAX_DLEN) and
can_frame_bytes(true, true, CANFD_MAX_DLEN).
In addition to the above:
- Use ISO 11898-1:2015 definitions for the names of the CAN frame
fields.
- Include linux/bits.h for use of BITS_PER_BYTE.
- Include linux/math.h for use of mult_frac() and
DIV_ROUND_UP(). N.B: the use of DIV_ROUND_UP() is not new to this
patch, but the include was previously omitted.
- Add copyright 2023 for myself.
Suggested-by: Thomas Kopp <Thomas.Kopp@microchip.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Thomas Kopp <Thomas.Kopp@microchip.com>
Link: https://lore.kernel.org/all/20230611025728.450837-4-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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This patch aligns code to match open parenthesis.
Link: https://lore.kernel.org/all/20230620131130.240180-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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can_put_echo_skb() checks for the enabled IFF_ECHO flag and the
correct ETH_P type of the given skbuff. When implementing the CAN XL
support the new check for ETH_P_CANXL has been forgotten.
Fixes: fb08cba12b52 ("can: canxl: update CAN infrastructure for CAN XL frames")
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20230506184515.39241-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Report an error to user space via netlink if the requested bit rate is
not supported by the device.
Link: https://lore.kernel.org/all/20230202110854.2318594-18-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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NL_SET_ERR_MSG_FMT()
Replace the netdev_err() by NL_SET_ERR_MSG_FMT() to better inform the
user about the problem. While there, use %u to print unsigned values
and improve error message a bit.
In case of an error, return -EINVAL instead of -EDOM, this corresponds
better to the actual meaning of the error value.
Link: https://lore.kernel.org/all/20230202110854.2318594-17-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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In the current code, if the user configures a bitrate, a default SJW
value of 1 is used. If the user configures both a bitrate and a SJW
value, can_calc_bittiming() silently limits the SJW value to SJW max
and TSEG2.
We came to the conclusion that if the user provided an invalid SJW
value, it's best to bail out and inform the user [1].
[1] https://lore.kernel.org/all/CAMZ6RqKqhmTgUZiwe5uqUjBDnhhC2iOjZ791+Y845btJYwVDKg@mail.gmail.com
Further the ISO 11898-1:2015 standard mandates that "SJW shall be less
than or equal to the minimum of these two items: Phase_Seg1 and
Phase_Seg2." [2] The current code is missing that check.
[2] https://lore.kernel.org/all/BL3PR11MB64844E3FC13C55433CDD0B3DFB449@BL3PR11MB6484.namprd11.prod.outlook.com
The previous patches introduced
1) can_sjw_set_default() - sets a default value for SJW if unset
2) can_sjw_check() - implements a SJW check against SJW max, Phase
Seg1 and Phase Seg2. In the error case this function reports the error
to user space via netlink.
Replace both the open-coded SJW default setting and the open-coded and
insufficient checks of SJW with the helper functions
can_sjw_set_default() and can_sjw_check().
Link: https://lore.kernel.org/all/20230202110854.2318594-16-mkl@pengutronix.de
Link: https://lore.kernel.org/all/CAMZ6RqKqhmTgUZiwe5uqUjBDnhhC2iOjZ791+Y845btJYwVDKg@mail.gmail.com
Link: https://lore.kernel.org/all/BL3PR11MB64844E3FC13C55433CDD0B3DFB449@BL3PR11MB6484.namprd11.prod.outlook.com
Suggested-by: Thomas Kopp <Thomas.Kopp@microchip.com>
Suggested-by: Vincent Mailhol <vincent.mailhol@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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"The (Re-)Synchronization Jump Width (SJW) defines how far a
resynchronization may move the Sample Point inside the limits defined
by the Phase Buffer Segments to compensate for edge phase errors." [1]
In other words, this means that the SJW parameter controls the
tolerance of the CAN controller to frequency errors compared to other
CAN controllers.
If the user space does not provide an SJW parameter, the kernel
chooses a default value of 1. This has proven to be a good default
value for classic CAN controllers, but no longer for modern CAN-FD
controllers.
In the past there were CAN controllers like the sja1000 with a rather
limited range of bit timing parameters. For the standard bit rates
this results in the following bit timing parameters:
| Bit timing parameters for sja1000 with 8.000000 MHz ref clock
| _----+--------------=> tseg1: 1 … 16
| / / _---------=> tseg2: 1 … 8
| | | / _-----=> sjw: 1 … 4
| | | | / _-=> brp: 1 … 64 (inc: 1)
| | | | | /
| nominal | | | | | real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error BTR0 BTR1
| 1000000 125 2 3 2 1 1 1000000 0.0% 75.0% 75.0% 0.0% 0x00 0x14
| 800000 125 3 4 2 1 1 800000 0.0% 80.0% 80.0% 0.0% 0x00 0x16
| 666666 125 4 4 3 1 1 666666 0.0% 80.0% 75.0% 6.2% 0x00 0x27
| 500000 125 6 7 2 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00 0x1c
| 250000 250 6 7 2 1 2 250000 0.0% 87.5% 87.5% 0.0% 0x01 0x1c
| 125000 500 6 7 2 1 4 125000 0.0% 87.5% 87.5% 0.0% 0x03 0x1c
| 100000 625 6 7 2 1 5 100000 0.0% 87.5% 87.5% 0.0% 0x04 0x1c
| 83333 750 6 7 2 1 6 83333 0.0% 87.5% 87.5% 0.0% 0x05 0x1c
| 50000 1250 6 7 2 1 10 50000 0.0% 87.5% 87.5% 0.0% 0x09 0x1c
| 33333 1875 6 7 2 1 15 33333 0.0% 87.5% 87.5% 0.0% 0x0e 0x1c
| 20000 3125 6 7 2 1 25 20000 0.0% 87.5% 87.5% 0.0% 0x18 0x1c
| 10000 6250 6 7 2 1 50 10000 0.0% 87.5% 87.5% 0.0% 0x31 0x1c
The attentive reader will notice that the SJW is 1 in most cases,
while the Seg2 phase is 2. Both values are given in TQ units, which in
turn is a duration in nanoseconds.
For example the 500 kbit/s configuration:
| nominal real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error BTR0 BTR1
| 500000 125 6 7 2 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00 0x1c
the TQ is 125ns, the Phase Seg2 is "2" (== 250ns), the SJW is "1" (==
125 ns).
Looking at a more modern CAN controller like a mcp2518fd, it has wider
bit timing registers.
| Bit timing parameters for mcp251xfd with 40.000000 MHz ref clock
| _----+--------------=> tseg1: 2 … 256
| / / _---------=> tseg2: 1 … 128
| | | / _-----=> sjw: 1 … 128
| | | | / _-=> brp: 1 … 256 (inc: 1)
| | | | | /
| nominal | | | | | real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error NBTCFG
| 500000 25 34 35 10 1 1 500000 0.0% 87.5% 87.5% 0.0% 0x00440900
The TQ is 25ns, the Phase Seg 2 is "10" (== 250ns), the SJW is "1" (==
25ns).
Since the kernel chooses a default SJW of 1 regardless of the TQ, this
leads to a much smaller SJW and thus much smaller tolerances to
frequency errors.
To maintain the same oscillator tolerances on controllers with wide
bit timing registers, select a default SJW value of Phase Seg2 / 2
unless Phase Seg 1 is less. This results in the following bit timing
parameters:
| Bit timing parameters for mcp251xfd with 40.000000 MHz ref clock
| _----+--------------=> tseg1: 2 … 256
| / / _---------=> tseg2: 1 … 128
| | | / _-----=> sjw: 1 … 128
| | | | / _-=> brp: 1 … 256 (inc: 1)
| | | | | /
| nominal | | | | | real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error NBTCFG
| 500000 25 34 35 10 5 1 500000 0.0% 87.5% 87.5% 0.0% 0x00440904
The TQ is 25ns, the Phase Seg 2 is "10" (== 250ns), the SJW is "5" (==
125ns). Which is the same as on the sja1000 controller.
[1] http://web.archive.org/http://www.oertel-halle.de/files/cia99paper.pdf
Link: https://lore.kernel.org/all/20230202110854.2318594-15-mkl@pengutronix.de
Cc: Mark Bath <mark@baggywrinkle.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Phase Buffer Segment
According to "The Configuration of the CAN Bit Timing" [1] the SJW
"may not be longer than either Phase Buffer Segment".
Check SJW against length of both Phase buffers. In case the SJW is
greater, report an error via netlink to user space and bail out.
[1] http://web.archive.org/http://www.oertel-halle.de/files/cia99paper.pdf
Link: https://lore.kernel.org/all/20230202110854.2318594-14-mkl@pengutronix.de
Suggested-by: Vincent Mailhol <vincent.mailhol@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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error value
If the user space has supplied an invalid SJW value (greater than the
maximum SJW value), report -EINVAL instead of -ERANGE, this better
matches the actual meaning of the error value.
Additionally report an error message via netlink to the user space.
Link: https://lore.kernel.org/all/20230202110854.2318594-13-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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harmonize error value
Check each bit timing parameter first individually against their
limits and report a meaningful error message via netlink to the user
space.
In case of an error, return -EINVAL instead of -ERANGE, this
corresponds better to the actual meaning of the error value.
Link: https://lore.kernel.org/all/20230202110854.2318594-12-mkl@pengutronix.de
Suggested-by: Vincent Mailhol <vincent.mailhol@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Factor out the functionality of assigning a SJW default value into
can_sjw_set_default() and the checking the SJW limits into
can_sjw_check().
This functions will be improved and called from a different function
in the following patches.
Link: https://lore.kernel.org/all/20230202110854.2318594-11-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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This is a preparation patch.
In order to pass warning/error messages during netlink calls back to
user space, pass the extack struct down the callstack of
can_changelink(), the actual error messages will be added in the
following ptaches.
Link: https://lore.kernel.org/all/20230202110854.2318594-10-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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NL_SET_ERR_MSG_FMT()
Since commit 51c352bdbcd2 ("netlink: add support for formatted extack
messages") formatted extack messages are supported to inform the user
space or warnings/errors during netlink calls.
Replace the netdev_err() by NL_SET_ERR_MSG_FMT() to better inform the
user about the problem. While there, use %u to print unsigned values
and improve error message a bit.
Link: https://lore.kernel.org/all/20230202110854.2318594-9-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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The sample point is a value in tenths of a percent. Meaningful values
are between 0 and 1000. Invalid values are rejected and an error
message is returned to user space via netlink.
Link: https://lore.kernel.org/all/20230202110854.2318594-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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constants are provided
The CAN driver framework supports either fixed bit rates or bit timing
constants. Bail out during driver registration if both are given.
Link: https://lore.kernel.org/all/20230202110854.2318594-7-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Implement the function can_bittiming_const_valid() to check the
validity of the specified bit timing constant. Call this function from
register_candev() to check the bit timing constants during the
registration of the CAN interface.
Link: https://lore.kernel.org/all/20230202110854.2318594-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Clean up the code flow a bit, don't assign err variable but directly
return. Remove the unneeded else, too.
Link: https://lore.kernel.org/all/20230202110854.2318594-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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The can_fixup_bittiming() function is used to validate the
user-supplied low-level bit timing parameters and calculate the
bitrate prescaler (brp) from the requested time quanta (tq) and the
CAN clock of the controller.
can_fixup_bittiming() selects the best matching integer bit rate
prescaler, which may result in a different time quantum than the value
specified by the user.
Calculate the resulting time quantum and assign it so that the user
sees the effective time quantum.
Link: https://lore.kernel.org/all/20230202110854.2318594-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Commit 1c47fa6b31c2 ("can: dev: add a helper function to calculate the
duration of one bit") made the constant CAN_SYNC_SEG available in a
header file.
The magic number 1 in can_fixup_bittiming() represents the width of
the sync segment, replace it by CAN_SYNC_SEG to make the code more
readable.
Link: https://lore.kernel.org/all/20230202110854.2318594-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Commit 1c47fa6b31c2 ("can: dev: add a helper function to calculate the
duration of one bit") added the helper function can_bit_time().
Replace open coded variants of can_bit_time() by the helper function.
Link: https://lore.kernel.org/all/20230202110854.2318594-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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In commit a6d190f8c767 ("can: skb: drop tx skb if in listen only
mode") the priv->ctrlmode element is read even on virtual CAN
interfaces that do not create the struct can_priv at startup. This
out-of-bounds read may lead to CAN frame drops for virtual CAN
interfaces like vcan and vxcan.
This patch mainly reverts the original commit and adds a new helper
for CAN interface drivers that provide the required information in
struct can_priv.
Fixes: a6d190f8c767 ("can: skb: drop tx skb if in listen only mode")
Reported-by: Dariusz Stojaczyk <Dariusz.Stojaczyk@opensynergy.com>
Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Cc: Max Staudt <max@enpas.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221102095431.36831-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org # 6.0.x
[mkl: patch pch_can, too]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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- add new ETH_P_CANXL ethernet protocol type
- update skb checks for CAN XL
- add alloc_canxl_skb() which now needs a data length parameter
- introduce init_can_skb_reserve() to reduce code duplication
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-6-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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To simplify the testing in user space all struct canfd_frame's provided by
the CAN subsystem of the Linux kernel now have the CANFD_FDF flag set in
canfd_frame::flags.
NB: Handcrafted ETH_P_CANFD frames introduced via PF_PACKET socket might
not set this bit correctly. During the check for sufficient headroom in
PF_PACKET sk_buffs the uninitialized CAN sk_buff data structures are filled.
In the case of a CAN FD frame the CANFD_FDF flag is set accordingly.
As the CAN frame content is already zero initialized in alloc_canfd_skb()
the obsolete initialization of cf->flags in the CTU CAN FD driver has been
removed as it would overwrite the already set CANFD_FDF flag.
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-4-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Add two helpers to retrieve the data length from CAN sk_buffs and prepare
the length information to be a uint16 value for the CAN XL support.
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-3-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Replace open coded checks for sk_buffs containing Classical CAN and
CAN FD frame structures as a preparation for CAN XL support.
With the added length check the unintended processing of CAN XL frames
having the CANXL_XLF bit set can be suppressed even when the skb->len
fits to non CAN XL frames.
The CAN_RAW socket needs a rework to use these helpers. Therefore the
use of these helpers is postponed to the CAN_RAW CAN XL integration.
The J1939 protocol gets a check for Classical CAN frames too.
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Fix typo "rounted" -> "rounded".
Link: https://lore.kernel.org/all/20220811093617.1861938-2-mkl@pengutronix.de
Fixes: d254586c3453 ("can: rx-offload: Add support for HW fifo based irq offloading")
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Tools based on libpcap (such as tcpdump) expect the SIOCSHWTSTAMP
ioctl call to be supported. This is also specified in the kernel doc
[1]. The purpose of this ioctl is to toggle the hardware timestamps.
Currently, CAN devices which support hardware timestamping have those
always activated. can_eth_ioctl_hwts() is a dumb function that will
always succeed when requested to set tx_type to HWTSTAMP_TX_ON or
rx_filter to HWTSTAMP_FILTER_ALL.
[1] Kernel doc: Timestamping, section 3.1 "Hardware Timestamping
Implementation: Device Drivers"
Link: https://docs.kernel.org/networking/timestamping.html#hardware-timestamping-implementation-device-drivers
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-9-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Add function can_ethtool_op_get_ts_info_hwts(). This function will be
used by CAN devices with hardware TX/RX timestamping support to
implement ethtool_ops::get_ts_info. This function does not offer
support to activate/deactivate hardware timestamps at device level nor
support the filter options (which is currently the case for all CAN
devices with hardware timestamping support).
The fact that hardware timestamp can not be deactivated at hardware
level does not impact the userland. As long as the user do not set
SO_TIMESTAMPING using a setsockopt() or ioctl(), the kernel will not
emit TX timestamps (RX timestamps will still be reproted as it is the
case currently).
Drivers which need more fine grained control remains free to implement
their own function, but we foresee that the generic function
introduced here will be sufficient for the majority.
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-8-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Because of the loopback feature of socket CAN, hardware TX timestamps
are nothing else than the hardware RX timespamp of the corresponding
loopback packet. This patch simply reuses the hardware RX timestamp.
The rationale to clone this timestamp value is that existing tools
which rely of libpcap (such as tcpdump) expect support for both TX and
RX hardware timestamps in order to activate the feature (i.e. no
granular control to activate either of TX or RX hardware timestamps).
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-7-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Upcoming changes on slcan driver will require you to specify a bitrate
of value -1 to prevent the open_candev() from failing but at the same
time highlighting that it is a fake value. In this case the command
`ip --details -s -s link show' would print 4294967295 as the bitrate
value. The patch change this value in 0.
Link: https://lore.kernel.org/all/20220628163137.413025-5-dario.binacchi@amarulasolutions.com
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Tested-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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do_set_data_bittiming callback
This patch is similar to 7e193a42c37c ("can: netlink: allow
configuring of fixed bit rates without need for do_set_bittiming
callback") but for data bit rates instead of bit rates.
Usually CAN devices support configurable data bit rates. The limits
are defined by struct can_priv::data_bittiming_const. Another way is
to implement the struct can_priv::do_set_data_bittiming callback.
If the bit rate is configured via netlink, the can_changelink()
function checks that either can_priv::data_bittiming_const or struct
can_priv::do_set_data_bittiming is implemented.
In commit 431af779256c ("can: dev: add CAN interface API for fixed
bitrates") an API for configuring bit rates on CAN interfaces that
only support fixed bit rates was added. The supported bit rates are
defined by struct can_priv::bitrate_const.
However the above mentioned commit forgot to add the struct
can_priv::data_bitrate_const to the check in can_changelink().
In order to avoid to implement a no-op can_priv::do_set_data_bittiming
callback on devices with fixed data bit rates, extend the check in
can_changelink() accordingly.
Link: https://lore.kernel.org/all/20220613143633.4151884-1-mkl@pengutronix.de
Fixes: 431af779256c ("can: dev: add CAN interface API for fixed bitrates")
Acked-by: Max Staudt <max@enpas.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Frames can be directly injected to a can driver via the packet
socket. By doing so, it is possible to reach the
net_device_ops::ndo_start_xmit function even if the driver is
configured in listen only mode.
Add a check in can_dropped_invalid_skb() to discard the skb if
CAN_CTRLMODE_LISTENONLY is set.
Link: https://lore.kernel.org/all/20220610143009.323579-8-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Max Staudt <max@enpas.org>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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The functions can_dropped_invalid_skb() and can_skb_headroom_valid()
grew a lot over the years to a point which it does not make much sense
to have them defined as static inline in header files. Move those two
functions to the .c counterpart of skb.h.
can_skb_headroom_valid()'s only caller being
can_dropped_invalid_skb(), the declaration is removed from the
header. Only can_dropped_invalid_skb() gets its symbol exported.
While doing so, do a small cleanup: add brackets around the else block
in can_dropped_invalid_skb().
Link: https://lore.kernel.org/all/20220610143009.323579-7-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Max Staudt <max@enpas.org>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Only a few drivers rely on the CAN rx offload framework (as of the
writing of this patch, only four: flexcan, m_can, mcp251xfd and
ti_hecc). Split it out of can-dev and add a new config symbol:
CAN_RX_OFFLOAD.
The drivers relying on CAN rx offload are in different sub
folders. Make CAN_RX_OFFLOAD an hidden option and tag all the drivers
depending on that feature with "select CAN_RX_OFFLOAD" so that the
option gets automatically enabled if and only if one of those drivers
is chosen.
Link: https://lore.kernel.org/all/20220610143009.323579-5-mailhol.vincent@wanadoo.fr
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Max Staudt <max@enpas.org>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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The canonical way to select or deselect an object during compilation
is to use this pattern in the relevant Makefile:
bar-$(CONFIG_FOO) := foo.o
bittiming.c instead uses some #ifdef CONFIG_CAN_CALC_BITTIMG.
Create a new file named calc_bittiming.c with all the functions which
are conditionally compiled with CONFIG_CAN_CALC_BITTIMG and modify the
Makefile according to above pattern.
Link: https://lore.kernel.org/all/20220610143009.323579-4-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Max Staudt <max@enpas.org>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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In the next patches, the software/virtual drivers (slcan, v(x)can)
will depend on drivers/net/can/dev/skb.o.
This patch changes the scope of the can-dev module to include the
above mentioned drivers.
To do so, we reuse the menu "CAN Device Drivers" and turn it into a
configmenu using the config symbol CAN_DEV (which we released in
previous patch). Also, add a description to this new CAN_DEV
menuconfig.
The symbol CAN_DEV now only triggers the build of skb.o. For this
reasons, all the macros from linux/module.h are deported from
drivers/net/can/dev/dev.c to drivers/net/can/dev/skb.c.
Finally, drivers/net/can/dev/Makefile is adjusted accordingly.
Link: https://lore.kernel.org/all/20220610143009.323579-3-mailhol.vincent@wanadoo.fr
Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Max Staudt <max@enpas.org>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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In the next patches, the scope of the can-dev module will grow to
engloble the software/virtual drivers (slcan, v(x)can). To this
extent, release CAN_DEV by renaming it into CAN_NETLINK. The config
symbol CAN_DEV will be reused to cover this extended scope.
The rationale for the name CAN_NETLINK is that netlink is the
predominant feature added here.
The current description only mentions platform drivers despite the
fact that this symbol is also required by "normal" devices (e.g. USB
or PCI) which do not fall under the platform devices category. The
description is updated accordingly to fix this gap.
Link: https://lore.kernel.org/all/20220610143009.323579-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Max Staudt <max@enpas.org>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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do_set_bittiming callback
Usually CAN devices support configurable bit rates. The limits are
defined by struct can_priv::bittiming_const. Another way is to
implement the struct can_priv::do_set_bittiming callback.
If the bit rate is configured via netlink, the can_changelink()
function checks that either can_priv::bittiming_const or struct
can_priv::do_set_bittiming is implemented.
In commit 431af779256c ("can: dev: add CAN interface API for fixed
bitrates") an API for configuring bit rates on CAN interfaces that
only support fixed bit rates was added. The supported bit rates are
defined by struct can_priv::bitrate_const.
However the above mentioned commit forgot to add the struct
can_priv::bitrate_const to the check in can_changelink().
In order to avoid to implement a no-op can_priv::do_set_bittiming
callback on devices with fixed bit rates, extend the check in
can_changelink() accordingly.
Link: https://lore.kernel.org/all/20220611144248.3924903-1-mkl@pengutronix.de
Fixes: 431af779256c ("can: dev: add CAN interface API for fixed bitrates")
Reported-by: Max Staudt <max@enpas.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Since commit 30f3b42147ba6f ("can: mark led trigger as broken") the
CAN specific LED support was disabled and marked as BROKEN. As the
common LED support with CONFIG_LEDS_TRIGGER_NETDEV should do this work
now the code can be removed as preparation for a CAN netdevice Kconfig
rework.
Link: https://lore.kernel.org/all/20220518154527.29046-1-socketcan@hartkopp.net
Suggested-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
[mkl: remove led.h from MAINTAINERS]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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We want to remove the weight argument from the basic version of the
netif_napi_add() call. Move all the callers in drivers/net/can that
pass a custom weight (i.e. not NAPI_POLL_WEIGHT or 64) to the
netif_napi_add_weight() API.
Link: https://lore.kernel.org/all/20220517002345.1812104-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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larger ones
The CiA (CAN in Automation) lists in their Newsletter 1/2018 in the
"Recommendation for the CAN FD bit-timing" [1] article several
recommendations, one of them is:
| Recommendation 3: Choose BRPA and BRPD as low as possible
[1] https://can-newsletter.org/uploads/media/raw/f6a36d1461371a2f86ef0011a513712c.pdf
With the current bit timing algorithm Srinivas Neeli noticed that on
the Xilinx Versal ACAP board the CAN data bit timing parameters are
not calculated optimally. For most bit rates, the bit rate
prescaler (BRP) is != 1, although it's possible to configure the
requested with a bit rate with a prescaler of 1:
| Data Bit timing parameters for xilinx_can_fd2i with 79.999999 MHz ref clock (cmd-line) using algo 'v4.8'
| nominal real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error
| 12000000 12 2 2 2 1 1 11428571 4.8% 75.0% 71.4% 4.8%
| 10000000 25 1 1 1 1 2 9999999 0.0% 75.0% 75.0% 0.0%
| 8000000 12 3 3 3 1 1 7999999 0.0% 75.0% 70.0% 6.7%
| 5000000 50 1 1 1 1 4 4999999 0.0% 75.0% 75.0% 0.0%
| 4000000 62 1 1 1 1 5 3999999 0.0% 75.0% 75.0% 0.0%
| 2000000 125 1 1 1 1 10 1999999 0.0% 75.0% 75.0% 0.0%
| 1000000 250 1 1 1 1 20 999999 0.0% 75.0% 75.0% 0.0%
The bit timing parameter calculation algorithm iterates effectively
from low to high BRP values. It selects a new best parameter set, if
the sample point error of the current parameter set is equal or less
to old best parameter set.
If the given hardware constraints (clock rate and bit timing parameter
constants) don't allow a sample point error of 0, the algorithm will
first find a valid bit timing parameter set with a low BRP, but then
will accept parameter sets with higher BRPs that have the same sample
point error.
This patch changes the algorithm to only accept a new parameter set,
if the resulting sample point error is lower. This leads to the
following data bit timing parameter for the Versal ACAP board:
| Data Bit timing parameters for xilinx_can_fd2i with 79.999999 MHz ref clock (cmd-line) using algo 'can-next'
| nominal real Bitrt nom real SampP
| Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error
| 12000000 12 2 2 2 1 1 11428571 4.8% 75.0% 71.4% 4.8%
| 10000000 12 2 3 2 1 1 9999999 0.0% 75.0% 75.0% 0.0%
| 8000000 12 3 3 3 1 1 7999999 0.0% 75.0% 70.0% 6.7%
| 5000000 12 5 6 4 1 1 4999999 0.0% 75.0% 75.0% 0.0%
| 4000000 12 7 7 5 1 1 3999999 0.0% 75.0% 75.0% 0.0%
| 2000000 12 14 15 10 1 1 1999999 0.0% 75.0% 75.0% 0.0%
| 1000000 25 14 15 10 1 2 999999 0.0% 75.0% 75.0% 0.0%
Note: Due to HW constraints a data bit rate of 1 MBit/s with BRP = 1 is not possible.
Link: https://lore.kernel.org/all/20220318144913.873614-1-mkl@pengutronix.de
Link: https://lore.kernel.org/all/20220113203004.jf2rqj2pirhgx72i@pengutronix.de
Cc: Srinivas Neeli <sneeli@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
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can_rx_offload_queue_timestamp()
This patch renames the function can_rx_offload_queue_sorted() to
can_rx_offload_queue_timestamp(). This better describes what the
function does, it adds a newly RX'ed skb to the sorted queue by its
timestamp.
Link: https://lore.kernel.org/all/20220417194327.2699059-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Since commit
baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.")
the function netif_rx() can be used in preemptible/thread context as
well as in interrupt context.
Use netif_rx().
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: linux-can@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
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This patch marks the arguments of some functions as well as some local
variables as constant.
Link: https://lore.kernel.org/all/20220124215642.3474154-7-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
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This patch simplifies the validation of the fixed bit rates. If a
supported bit rate is found, directly return 0.
If no valid bit rate is found return -EINVAL;
Link: https://lore.kernel.org/all/20220124215642.3474154-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
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Currently, the CAN netlink interface provides no easy ways to check
the capabilities of a given controller. The only method from the
command line is to try each CAN_CTRLMODE_* individually to check
whether the netlink interface returns an -EOPNOTSUPP error or not
(alternatively, one may find it easier to directly check the source
code of the driver instead...)
This patch introduces a method for the user to check both the
supported and the static capabilities. The proposed method introduces
a new IFLA nest: IFLA_CAN_CTRLMODE_EXT which extends the current
IFLA_CAN_CTRLMODE. This is done to guaranty a full forward and
backward compatibility between the kernel and the user land
applications.
The IFLA_CAN_CTRLMODE_EXT nest contains one single entry:
IFLA_CAN_CTRLMODE_SUPPORTED. Because this entry is only used in one
direction: kernel to userland, no new struct nla_policy are
introduced.
Below table explains how IFLA_CAN_CTRLMODE_SUPPORTED (hereafter:
"supported") and can_ctrlmode::flags (hereafter: "flags") allow us to
identify both the supported and the static capabilities, when masked
with any of the CAN_CTRLMODE_* bit flags:
supported & flags & Controller capabilities
CAN_CTRLMODE_* CAN_CTRLMODE_*
-----------------------------------------------------------------------
false false Feature not supported (always disabled)
false true Static feature (always enabled)
true false Feature supported but disabled
true true Feature supported and enabled
Link: https://lore.kernel.org/all/20211213160226.56219-5-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
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The statically enabled features of a CAN controller can be retrieved
using below formula:
| u32 ctrlmode_static = priv->ctrlmode & ~priv->ctrlmode_supported;
As such, there is no need to store this information. This patch remove
the field ctrlmode_static of struct can_priv and provides, in
replacement, the inline function can_get_static_ctrlmode() which
returns the same value.
Link: https://lore.kernel.org/all/20211213160226.56219-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
|
The actual payload length of the CAN Remote Transmission Request (RTR)
frames is always 0, i.e. no payload is transmitted on the wire.
However, those RTR frames still use the DLC to indicate the length of
the requested frame.
As such, net_device_stats::rx_bytes should not be increased for the
RTR frames.
This patch fixes all the CAN drivers.
Link: https://lore.kernel.org/all/20211207121531.42941-5-mailhol.vincent@wanadoo.fr
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Yasushi SHOJI <yashi@spacecubics.com>
Cc: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
Cc: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
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The CAN error message frames (i.e. error skb) are an interface
specific to socket CAN. The payload of the CAN error message frames
does not correspond to any actual data sent on the wire. Only an error
flag and a delimiter are transmitted when an error occurs (c.f. ISO
11898-1 section 10.4.4.2 "Error flag").
For this reason, it makes no sense to increment the rx_packets and
rx_bytes fields of struct net_device_stats because no actual payload
were transmitted on the wire.
This patch fixes all the CAN drivers.
Link: https://lore.kernel.org/all/20211207121531.42941-2-mailhol.vincent@wanadoo.fr
CC: Marc Kleine-Budde <mkl@pengutronix.de>
CC: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Alexandre Belloni <alexandre.belloni@bootlin.com>
CC: Ludovic Desroches <ludovic.desroches@microchip.com>
CC: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
CC: Maxime Ripard <mripard@kernel.org>
CC: Chen-Yu Tsai <wens@csie.org>
CC: Jernej Skrabec <jernej.skrabec@gmail.com>
CC: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
CC: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
CC: Michal Simek <michal.simek@xilinx.com>
CC: Stephane Grosjean <s.grosjean@peak-system.com>
Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
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In [1], we introduced a set of units in linux/can/bittiming.h. Since
then, generic SI prefixes were added to linux/units.h in [2]. Those
new prefixes can perfectly replace CAN specific ones.
This patch replaces all occurrences of the CAN units with their
corresponding prefix (from linux/units) and the unit (as a comment)
according to below table.
CAN units SI metric prefix (from linux/units) + unit (as a comment)
------------------------------------------------------------------------
CAN_KBPS KILO /* BPS */
CAN_MBPS MEGA /* BPS */
CAM_MHZ MEGA /* Hz */
The definition are then removed from linux/can/bittiming.h
[1] commit 1d7750760b70 ("can: bittiming: add CAN_KBPS, CAN_MBPS and
CAN_MHZ macros")
[2] commit 26471d4a6cf8 ("units: Add SI metric prefix definitions")
Link: https://lore.kernel.org/all/20211124014536.782550-1-mailhol.vincent@wanadoo.fr
Suggested-by: Jimmy Assarsson <extja@kvaser.com>
Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
|
