The function mcp251xfd_chip_wait_for_osc_ready() polls the Oscillator
Control Register for the oscillator to get ready.
This is the first register the driver reads from. Reading implausible
values (all bits set or unset) can be caused by the chip starting up
after power on, waking up after sleep, or by the chip not being preset
at all. Add check for implausible register content
mcp251xfd_reg_invalid() to the regmap_read_poll_timeout() loop.
In case of a regmap_read_poll_timeout() returns a fatal error (and not
a timeout), forward it to the caller.
As mcp251xfd_chip_wait_for_osc_ready() will be called after the probe
function has finished, (currently during ifup), move error message
about failed chip detection from there into the probe function.
Link: https://lore.kernel.org/all/20220207131047.282110-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The mcp251xfd_chip_stop() function tries the best to stop the chip and
put it into sleep mode. It continues, even if some intermediate steps
fail. As none of the callers use the return value, let this function
return void.
Link: https://lore.kernel.org/all/20220207131047.282110-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The mcp251xfd driver supports runtime PM enabled kernels, but also
works on !CONFIG_PM configurations.
This patch simplifies the runtime PM handling in the
mcp251xfd_unregister(). In the CONFIG_PM case, runtime PM has been
enabled in the mcp251xfd_probe() function, so we can disable it here.
For !CONFIG_PM builds call mcp251xfd_clks_and_vdd_disable() directly.
Link: https://lore.kernel.org/all/20220207131047.282110-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
MCP251XFD_REG_OSC is the first register the driver reads from. The
chip may be in deep sleep and the SPI transfer (i.e. the assertion of
the CS) will wake the chip up. This takes about 3ms. The CRC of this
transfer is wrong, or there isn't any chip at all, in this case the
CRC will be wrong, too. The driver ignores the CRC error and returns
the read data to the caller.
To avoid any confusion, this patch changes the
mcp251xfd_regmap_crc_read() function to only ignore the CRC error if
solely the OSC register is read. So when reading more than the OSC
registers at once, CRC errors are not ignored.
Link: https://lore.kernel.org/all/20220207131047.282110-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch renames mcp251xfd_osc_invalid() to mcp251xfd_reg_invalid(),
as it will be used for other registers than the "osc" register in a
later patch.
This patch also moves this function to more towards the beginning of
the file, to be available for other functions, too.
Link: https://lore.kernel.org/all/20220207131047.282110-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
A RX overflow usually happens during high system load. Printing
overflow messages to the kernel log, which on embedded systems often
is outputted on the serial console, even increases the system load.
To decrease the system load in these situations, denote the messages
to debug level and wrap them with net_ratelimit().
Link: https://lore.kernel.org/all/20220105154300.1258636-7-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch exchanges the order of open_candev() and
pm_runtime_get_sync(), so that open_candev() is called first.
A usual reason why open_candev() fails is missing CAN bit rate
configuration. It makes no sense to resume the device from PM sleep
first just to put it to sleep if the bit rate is not configured.
Link: https://lore.kernel.org/all/20220105154300.1258636-5-mkl@pengutronix.de
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::tx_bytes should not be increased when
sending RTR frames.
The function can_get_echo_skb() already returns the correct length,
even for RTR frames (c.f. [1]). However, for historical reasons, the
drivers do not use can_get_echo_skb()'s return value and instead, most
of them store a temporary length (or dlc) in some local structure or
array. Using the return value of can_get_echo_skb() solves the
issue. After doing this, such length/dlc fields become unused and so
this patch does the adequate cleaning when needed.
This patch fixes all the CAN drivers.
Finally, can_get_echo_skb() is decorated with the __must_check
attribute in order to force future drivers to correctly use its return
value (else the compiler would emit a warning).
[1] commit ed3320cec2 ("can: dev: __can_get_echo_skb():
fix real payload length return value for RTR frames")
Link: https://lore.kernel.org/all/20211207121531.42941-6-mailhol.vincent@wanadoo.fr
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.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: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Cc: Andreas Larsson <andreas@gaisler.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
[mkl: add conversion for grcan]
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.
For this reason, it is incorrect to copy the payload of RTR frames
(the payload buffer would only contain garbage data). This patch
encapsulates the payload copy in a check toward the RTR flag.
Link: https://lore.kernel.org/all/20211207121531.42941-4-mailhol.vincent@wanadoo.fr
Cc: Yasushi SHOJI <yashi@spacecubics.com>
Tested-by: Yasushi SHOJI <yashi@spacecubics.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
It's not clear what was the intention of redundant usage of IS_ERR()
around the clock pointer since with the error check of devm_clk_get()
followed by bailout it can't be invalid,
Simplify the code which fetches the input clock by using
devm_clk_get_optional(). It will allow to switch to device properties
approach in the future.
Link: https://lore.kernel.org/all/20211206165542.69887-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The function can_rx_offload_threaded_irq_finish() is needed to trigger
the NAPI thread to deliver read CAN frames to the networking stack.
This patch adds the missing call to can_rx_offload_threaded_irq_finish()
in case of a bus off, before leaving the interrupt handler to avoid
packet starvation.
Link: https://lore.kernel.org/all/20211106201526.44292-1-mkl@pengutronix.de
Fixes: 30bfec4fec ("can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
After reading all CAN frames from the controller in the IRQ handler
and storing them into a skb_queue, the driver calls napi_schedule().
In the napi poll function the skb from the skb_queue are then pushed
into the networking stack.
However if napi_schedule() is called from a threaded IRQ handler this
triggers the following error:
| NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!!
To avoid this, create a new rx-offload
function (can_rx_offload_threaded_irq_finish()) with a call to
local_bh_disable()/local_bh_enable() around the napi_schedule() call.
Convert all drivers that call can_rx_offload_irq_finish() from
threaded IRQ context to can_rx_offload_threaded_irq_finish().
Link: https://lore.kernel.org/r/20210724204745.736053-4-mkl@pengutronix.de
Suggested-by: Daniel Glöckner <dg@emlix.com>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In case an error occurred in the IRQ handler, the chip status is
dumped via devcoredump and all IRQs are disabled, but the chip stays
powered for further analysis.
The chip is in an undefined state and will not receive any CAN frames,
so shut down the timestamping worker, which reads the TBC register
regularly, too. This avoids any CRC read error messages if there is a
communication problem with the chip.
Fixes: efd8d98dfb ("can: mcp251xfd: add HW timestamp infrastructure")
Link: https://lore.kernel.org/r/20210724155131.471303-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch fixes the following clang warning, by marking the functions
as maybe unused. gcc doesn't complain about unused inline functions.
| drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c:564:1: warning: unused function 'mcp251xfd_chip_set_mode_nowait' [-Wunused-function]
| mcp251xfd_chip_set_mode_nowait(const struct mcp251xfd_priv *priv,
| ^
| 1 warning generated.
Link: https://lore.kernel.org/r/20210514153741.1958041-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Since 8ce8c0abcb the driver queues work via priv->restart_work when
resuming after suspend, even when the interface was not previously
enabled. This causes a null dereference error as the workqueue is only
allocated and initialized in mcp251x_open().
To fix this we move the workqueue init to mcp251x_can_probe() as there
is no reason to do it later and repeat it whenever mcp251x_open() is
called.
Fixes: 8ce8c0abcb ("can: mcp251x: only reset hardware as required")
Link: https://lore.kernel.org/r/17d5d714-b468-482f-f37a-482e3d6df84e@kontron.de
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[mkl: fix error handling in mcp251x_stop()]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
When we converted this code to use dev_err_probe() we accidentally
removed a return. It means that if devm_clk_get() it will lead to an
Oops when we call clk_get_rate() on the next line.
Fixes: cf8ee6de25 ("can: mcp251xfd: mcp251xfd_probe(): use dev_err_probe() to simplify error handling")
Link: https://lore.kernel.org/r/YJANZf13Qxd5Mhr1@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Conflicts:
MAINTAINERS
- keep Chandrasekar
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
- simple fix + trust the code re-added to param.c in -next is fine
include/linux/bpf.h
- trivial
include/linux/ethtool.h
- trivial, fix kdoc while at it
include/linux/skmsg.h
- move to relevant place in tcp.c, comment re-wrapped
net/core/skmsg.c
- add the sk = sk // sk = NULL around calls
net/tipc/crypto.c
- trivial
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MCP251XFD_REG_TBC is the time base counter register. It increments
once per SYS clock tick, which is 20 or 40 MHz. Observation shows that
if the lowest byte (which is transferred first on the SPI bus) of that
register is 0x00 or 0x80 the calculated CRC doesn't always match the
transferred one.
To reproduce this problem let the driver read the TBC register in a
high frequency. This can be done by attaching only the mcp251xfd CAN
controller to a valid terminated CAN bus and send a single CAN frame.
As there are no other CAN controller on the bus, the sent CAN frame is
not ACKed and the mcp251xfd repeats it. If user space enables the bus
error reporting, each of the NACK errors is reported with a time
stamp (which is read from the TBC register) to user space.
$ ip link set can0 down
$ ip link set can0 up type can bitrate 500000 berr-reporting on
$ cansend can0 4FF#ff.01.00.00.00.00.00.00
This leads to several error messages per second:
| mcp251xfd spi0.0 can0: CRC read error at address 0x0010 (length=4, data=00 3a 86 da, CRC=0x7753) retrying.
| mcp251xfd spi0.0 can0: CRC read error at address 0x0010 (length=4, data=80 01 b4 da, CRC=0x5830) retrying.
| mcp251xfd spi0.0 can0: CRC read error at address 0x0010 (length=4, data=00 e9 23 db, CRC=0xa723) retrying.
| mcp251xfd spi0.0 can0: CRC read error at address 0x0010 (length=4, data=00 8a 30 db, CRC=0x4a9c) retrying.
| mcp251xfd spi0.0 can0: CRC read error at address 0x0010 (length=4, data=80 f3 43 db, CRC=0x66d2) retrying.
If the highest bit in the lowest byte is flipped the transferred CRC
matches the calculated one. We assume for now the CRC calculation in
the chip works on wrong data and the transferred data is correct.
This patch implements the following workaround:
- If a CRC read error on the TBC register is detected and the lowest
byte is 0x00 or 0x80, the highest bit of the lowest byte is flipped
and the CRC is calculated again.
- If the CRC now matches, the _original_ data is passed to the reader.
For now we assume transferred data was OK.
Link: https://lore.kernel.org/r/20210406110617.1865592-5-mkl@pengutronix.de
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Thomas Kopp <thomas.kopp@microchip.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
