Marc Kleine-Budde says:
====================
pull-request: can-next 2025-01-10
Pierre-Henry Moussay adds PIC64GX compatibility to the DT bindings for
Microchip's mpfs-can IP core.
The next 3 patches are by Sean Nyekjaer and target the tcan4x5x
driver. First the DT bindings is converted to DT schema, then nWKRQ
voltage selection is added to the driver.
Dario Binacchi's patch for the sun4i_can makes the driver more
consistent by adding a likely() to the driver.
Another patch by Sean Nyekjaer for the tcan4x5x driver gets rid of a
false error message.
Charan Pedumuru converts the atmel-can DT bindings to DT schema.
The next 2 patches are by Oliver Hartkopp. The first one maps Oliver's
former mail addresses to a dedicated CAN mail address. The second one
assigns net/sched/em_canid.c additionally to the CAN maintainers.
Ariel Otilibili's patch removes dead code from the CAN dev helper.
The next 3 patches are by Sean Nyekjaer and add HW standby support to
the tcan4x5x driver.
A patch by Dario Binacchi fixes the DT bindings for the st,stm32-bxcan
driver.
The last 4 patches are by Jimmy Assarsson and target the kvaser_usb
and the kvaser_pciefd driver: error statistics are improved and
CAN_CTRLMODE_BERR_REPORTING is added.
* tag 'linux-can-next-for-6.14-20250110' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next:
can: kvaser_pciefd: Add support for CAN_CTRLMODE_BERR_REPORTING
can: kvaser_pciefd: Update stats and state even if alloc_can_err_skb() fails
can: kvaser_usb: Add support for CAN_CTRLMODE_BERR_REPORTING
can: kvaser_usb: Update stats and state even if alloc_can_err_skb() fails
dt-bindings: can: st,stm32-bxcan: fix st,gcan property type
can: m_can: call deinit/init callback when going into suspend/resume
can: tcan4x5x: add deinit callback to set standby mode
can: m_can: add deinit callback
can: dev: can_get_state_str(): Remove dead code
MAINTAINERS: assign em_canid.c additionally to CAN maintainers
mailmap: add an entry for Oliver Hartkopp
dt-bindings: net: can: atmel: Convert to json schema
can: tcan4x5x: get rid of false clock errors
can: sun4i_can: continue to use likely() to check skb
can: tcan4x5x: add option for selecting nWKRQ voltage
dt-bindings: can: tcan4x5x: Document the ti,nwkrq-voltage-vio option
dt-bindings: can: convert tcan4x5x.txt to DT schema
dt-bindings: can: mpfs: add PIC64GX CAN compatibility
====================
Link: https://patch.msgid.link/20250110112712.3214173-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In commit 6e86a1543c ("can: dev: provide optional GPIO based
termination support") GPIO based termination support was added.
For no particular reason that patch uses gpiod_set_value() to set the
GPIO. This leads to the following warning, if the systems uses a
sleeping GPIO, i.e. behind an I2C port expander:
| WARNING: CPU: 0 PID: 379 at /drivers/gpio/gpiolib.c:3496 gpiod_set_value+0x50/0x6c
| CPU: 0 UID: 0 PID: 379 Comm: ip Not tainted 6.11.0-20241016-1 #1 823affae360cc91126e4d316d7a614a8bf86236c
Replace gpiod_set_value() by gpiod_set_value_cansleep() to allow the
use of sleeping GPIOs.
Cc: Nicolai Buchwitz <nb@tipi-net.de>
Cc: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Cc: stable@vger.kernel.org
Reported-by: Leonard Göhrs <l.goehrs@pengutronix.de>
Tested-by: Leonard Göhrs <l.goehrs@pengutronix.de>
Fixes: 6e86a1543c ("can: dev: provide optional GPIO based termination support")
Link: https://patch.msgid.link/20241121-dev-fix-can_set_termination-v1-1-41fa6e29216d@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch moves the evaluation of data[IFLA_CAN_CTRLMODE] in function
can_changelink in front of the evaluation of data[IFLA_CAN_BITTIMING].
This avoids a call to do_set_data_bittiming providing a stale
can_priv::ctrlmode with a CAN_CTRLMODE_FD flag not matching the
requested state when switching between a CAN Classic and CAN-FD bitrate.
In the same manner the evaluation of data[IFLA_CAN_CTRLMODE] in function
can_validate is also moved in front of the evaluation of
data[IFLA_CAN_BITTIMING].
This is a preparation for patches where the nominal and data bittiming
may have interdependencies on the driver side depending on the
CAN_CTRLMODE_FD flag state.
Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Link: https://patch.msgid.link/20240808164224.213522-1-stefan.maetje@esd.eu
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.
Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some CAN controllers do not have a register that contains the current
CAN state, but only a register that contains the error counters.
Introduce a new function can_state_get_by_berr_counter() that returns
the current TX and RX state depending on the provided CAN bit error
counters.
Link: https://lore.kernel.org/all/20231005-at91_can-rx_offload-v2-1-9987d53600e0@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This race condition was discovered while updating the at91_can driver
to use can_bus_off(). The following scenario describes how the
converted at91_can driver would behave.
When a CAN device goes into BUS-OFF state, the driver usually
stops/resets the CAN device and calls can_bus_off().
This function sets the netif carrier to off, and (if configured by
user space) schedules a delayed work that calls can_restart() to
restart the CAN device.
The can_restart() function first checks if the carrier is off and
triggers an error message if the carrier is OK.
Then it calls the driver's do_set_mode() function to restart the
device, then it sets the netif carrier to on. There is a race window
between these two calls.
The at91 CAN controller (observed on the sama5d3, a single core 32 bit
ARM CPU) has a hardware limitation. If the device goes into bus-off
while sending a CAN frame, there is no way to abort the sending of
this frame. After the controller is enabled again, another attempt is
made to send it.
If the bus is still faulty, the device immediately goes back to the
bus-off state. The driver calls can_bus_off(), the netif carrier is
switched off and another can_restart is scheduled. This occurs within
the race window before the original can_restart() handler marks the
netif carrier as OK. This would cause the 2nd can_restart() to be
called with an OK netif carrier, resulting in an error message.
The flow of the 1st can_restart() looks like this:
can_restart()
// bail out if netif_carrier is OK
netif_carrier_ok(dev)
priv->do_set_mode(dev, CAN_MODE_START)
// enable CAN controller
// sama5d3 restarts sending old message
// CAN devices goes into BUS_OFF, triggers IRQ
// IRQ handler start
at91_irq()
at91_irq_err_line()
can_bus_off()
netif_carrier_off()
schedule_delayed_work()
// IRQ handler end
netif_carrier_on()
The 2nd can_restart() will be called with an OK netif carrier and the
error message will be printed.
To close the race window, first set the netif carrier to on, then
restart the controller. In case the restart fails with an error code,
roll back the netif carrier to off.
Fixes: 39549eef35 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-2-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
During testing, I triggered a can_restart() with the netif carrier
being OK [1]. The BUG_ON, which checks if the carrier is OK, results
in a fatal kernel crash. This is neither helpful for debugging nor for
a production system.
[1] The root cause is a race condition in can_restart() which will be
fixed in the next patch.
Do not crash the kernel, issue an error message instead, and continue
restarting the CAN device anyway.
Fixes: 39549eef35 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-1-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Rename the rx_offload_get_echo_skb() function to
can_rx_offload_get_echo_skb_queue_timestamp(), since it inserts the
echo skb into the rx-offload queue sorted by timestamp.
This is a preparation for adding
can_rx_offload_get_echo_skb_queue_tail(), which adds the echo skb to
the end of the queue. This is intended for devices that do not support
timestamps.
Link: https://lore.kernel.org/all/20230718-gs_usb-rx-offload-v2-1-716e542d14d5@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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>
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>
"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>
