In order to optimize FIFO access, especially on m_can cores attached
to slow busses like SPI, in patch
| e39381770e ("can: m_can: Disable IRQs on FIFO bus errors")
bulk read/write support has been added to the m_can_fifo_{read,write}
functions.
That change leads to the tcan driver to call
regmap_bulk_{read,write}() with a length of 0 (for CAN frames with 0
data length). regmap treats this as an error:
| tcan4x5x spi1.0 tcan4x5x0: FIFO write returned -22
This patch fixes the problem by not calling the
cdev->ops->{read,write)_fifo() in case of a 0 length read/write.
Fixes: e39381770e ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20220114155751.2651888-1-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Reported-by: Michael Anochin <anochin@photo-meter.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Previous patch removed can_priv::ctrlmode_static to replace it with
can_get_static_ctrlmode().
A condition sine qua non for this to work is that the controller
static modes should never be set in can_priv::ctrlmode_supported
(c.f. the comment on can_priv::ctrlmode_supported which states that it
is for "options that can be *modified* by netlink"). Also, this
condition is already correctly fulfilled by all existing drivers
which rely on the ctrlmode_static feature.
Nonetheless, we added an extra safeguard in can_set_static_ctrlmode()
to return an error value and to warn the developer who would be
adventurous enough to set to static a given feature that is already
set to supported.
The drivers which rely on the static controller mode are then updated
to check the return value of can_set_static_ctrlmode().
Link: https://lore.kernel.org/all/20211213160226.56219-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In m_can_read_fifo(), if the second call to m_can_fifo_read() fails,
the function jump to the out_fail label and returns without calling
m_can_receive_skb(). This means that the skb previously allocated by
alloc_can_skb() is not freed. In other terms, this is a memory leak.
This patch adds a goto label to destroy the skb if an error occurs.
Issue was found with GCC -fanalyzer, please follow the link below for
details.
Fixes: e39381770e ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20211107050755.70655-1-mailhol.vincent@wanadoo.fr
Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
With the design of this driver, this condition is often triggered.
However, the counter that this interrupt indicates an overflow is never
read either, so overflowing is harmless.
On my system, when a CAN bus starts flapping up and down, this locks up
the whole system with lots of interrupts and printks.
Specifically, this interrupt indicates the CEL field of ECR has
overflowed. All reads of ECR mask out CEL.
Fixes: e0d1f4816f ("can: m_can: add Bosch M_CAN controller support")
Link: https://lore.kernel.org/all/20211129222628.7490-1-brian.silverman@bluerivertech.com
Cc: stable@vger.kernel.org
Signed-off-by: Brian Silverman <brian.silverman@bluerivertech.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
On peripherals communicating over a relatively slow SPI line
(e.g. tcan4x5x), individual transfers have high fixed costs.
This causes the driver to spend most of its time waiting between
transfers and severely limits throughput.
Reduce these overheads by reading more than one word at a time.
Writing could get a similar treatment in follow-on commits.
Link: https://lore.kernel.org/r/20210817050853.14875-3-matt@bitbashing.io
Signed-off-by: Matt Kline <matt@bitbashing.io>
[mkl: remove __packed from struct id_and_dlc]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
If FIFO reads or writes fail due to the underlying regmap (e.g., SPI)
I/O, propagate that up to the m_can driver, log an error, and disable
interrupts, similar to the mcp251xfd driver.
While reworking the FIFO functions to add this error handling,
add support for bulk reads and writes of multiple registers.
Link: https://lore.kernel.org/r/20210817050853.14875-2-matt@bitbashing.io
Signed-off-by: Matt Kline <matt@bitbashing.io>
[mkl: re-wrap long lines, remove WARN_ON, convert to netdev block comments]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Since commit aee2b3ccc8 ("can: tcan4x5x: fix bittiming const, use
common bittiming from m_can driver") there is no use of the device
specific bit timing parameters (m_can_classdev::bit_timing and struct
m_can_classdev::data_timing).
This patch removes the support for custom bit timing from the driver,
as the common bit timing works for all known IP core implementations.
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Link: https://lore.kernel.org/r/20210616102811.2449426-7-mkl@pengutronix.de
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>
Introduce masks for the three RXESC fields (RBDS, F1DS, F0DS) and the
one TXESC field (TBDS). Update m_can_chip_config() to explicitly set all
four fields to the 64-byte option (0x7) (and these defs are renamed to
be more concise).
This is an improvement in maintainability, and also makes it easier to
implement more flexible configuration of the M_CAN buffers in the
future.
Link: https://lore.kernel.org/r/20210504125123.500553-4-torin@maxiluxsystems.com
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The m_can_start_xmit() function checks if the cdev->tx_skb is NULL and
returns with NETDEV_TX_BUSY in case tx_sbk is not NULL.
There is a race condition in the m_can_tx_work_queue(), where first
the skb is send to the driver and then the case tx_sbk is set to NULL.
A TX complete IRQ might come in between and wake the queue, which
results in tx_skb not being cleared yet.
Fixes: f524f829b7 ("can: m_can: Create a m_can platform framework")
Tested-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In commit 1be37d3b04 ("can: m_can: fix periph RX path: use
rx-offload to ensure skbs are sent from softirq context") the RX path
for peripherals (i.e. SPI based m_can controllers) was converted to
the rx-offload infrastructure. However, the error handling for
can_rx_offload_queue_sorted() was forgotten.
can_rx_offload_queue_sorted() will return with an error if the
internal queue is full.
This patch adds the missing error handling, by increasing the
rx_fifo_errors.
Fixes: 1be37d3b04 ("can: m_can: fix periph RX path: use rx-offload to ensure skbs are sent from softirq context")
Link: https://lore.kernel.org/r/20210401084515.1455013-1-mkl@pengutronix.de
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1503583 ("Error handling issues")
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
For peripheral devices, m_can sent skbs directly from a threaded irq
instead of from a softirq context, breaking the tcan4x5x peripheral
driver completely. This patch transitions the driver to use the
rx-offload helper for peripherals, ensuring the skbs are sent from the
correct context, with h/w timestamping to ensure correct ordering.
Link: https://lore.kernel.org/r/20210308102427.63916-4-torin@maxiluxsystems.com
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
[mkl: m_can_class_register(): update error handling]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This is a prerequisite for transitioning the m_can driver to rx-offload,
which works best with TX and RX timestamps.
The timestamps provided by M_CAN are 16-bit, timed according to the
nominal bit timing, and may be prescaled by a multiplier up to 16. We
choose the highest prescalar so that the timestamp wraps every 2^20 bit
times, or 209 ms at a bus speed of 5 Mbit/s. Timestamps will have a
precision of 16 bit times.
Link: https://lore.kernel.org/r/20210308102427.63916-3-torin@maxiluxsystems.com
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In order to implement byte queue limits (bql) in CAN drivers, the
length of the CAN frame needs to be passed into the networking stack
even if the transmission failed for some reason.
To avoid to calculate this length twice, extend can_free_echo_skb() to
return that value. Convert all users of this function, too.
This patch is the natural extension of commit:
| 9420e1d495 ("can: dev: can_get_echo_skb(): extend to return can
| frame length")
Link: https://lore.kernel.org/r/20210319142700.305648-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
For M_CAN peripherals, m_can_rx_handler() was called with quota = 1,
which caused any error handling to block RX from taking place until
the next time the IRQ handler is called. This had been observed to
cause RX to be blocked indefinitely in some cases.
This is fixed by calling m_can_rx_handler with a sensibly high quota.
Fixes: f524f829b7 ("can: m_can: Create a m_can platform framework")
Link: https://lore.kernel.org/r/20210303144350.4093750-1-torin@maxiluxsystems.com
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Message loss from RX FIFO 0 is already handled in
m_can_handle_lost_msg(), with netdev output included.
Removing this warning also improves driver performance under heavy
load, where m_can_do_rx_poll() may be called many times before this
interrupt is cleared, causing this message to be output many
times (thanks Mariusz Madej for this report).
Fixes: e0d1f4816f ("can: m_can: add Bosch M_CAN controller support")
Link: https://lore.kernel.org/r/20210303103151.3760532-1-torin@maxiluxsystems.com
Reported-by: Mariusz Madej <mariusz.madej@xtrack.com>
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.
To avoid to calculate this length twice, extend can_get_echo_skb() to return
that value. Convert all users of this function, too.
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The m_can driver's suspend and resume functions (m_can_class_suspend() and
m_can_class_resume()) make use of dev_get_drvdata() and assume that the drvdata
is a pointer to the struct net_device.
With upcoming conversion of the tcan4x5x driver to pm_runtime this assumption
is no longer valid. As the suspend and resume functions actually need a struct
m_can_classdev pointer, change the m_can_platform and the m_can_pci driver to
hold a pointer to struct m_can_classdev instead, as the tcan4x5x driver already
does.
Link: https://lore.kernel.org/r/20201212175518.139651-8-mkl@pengutronix.de
Reviewed-by: Sean Nyekjaer <sean@geanix.com>
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This is a preparatory patch for upcoming PCI based M_CAN devices. The current
PM implementation would cause PCI based drivers to enable PM twice, once when
the PCI device is added and a second time in m_can_class_register(). This will
cause 'Unbalanced pm_runtime_enable!' to be logged, and is a situation that
should be avoided.
Therefore, in anticipation of PCI devices, move PM enabling out from M_CAN
class registration to its only user, the m_can_platform driver.
Signed-off-by: Patrik Flykt <patrik.flykt@linux.intel.com>
Link: https://lore.kernel.org/r/20201023115800.46538-2-patrik.flykt@linux.intel.com
[mkl: m_can_plat_probe(): fix error handling
m_can_class_register(): simplify error handling]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Trivial conflict in CAN, keep the net-next + the byteswap wrapper.
Conflicts:
drivers/net/can/usb/gs_usb.c
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
At lest the revision 3.3.0 of the bosch m_can IP core specifies that valid
register values for "Nominal Time segment after sample point (NTSEG2)" are from
1 to 127. As the hardware uses a value of one more than the programmed value,
mean tseg2_min is 2.
This patch fixes the tseg2_min value accordingly.
Cc: Dan Murphy <dmurphy@ti.com>
Cc: Mario Huettel <mario.huettel@gmx.net>
Acked-by: Sriram Dash <sriram.dash@samsung.com>
Link: https://lore.kernel.org/r/20201124190751.3972238-1-mkl@pengutronix.de
Fixes: b03cfc5bb0 ("can: m_can: Enable M_CAN version dependent initialization")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The threaded IRQ handler is used for the tcan4x5x driver only. The IRQ pin of
the tcan4x5x controller is active low, so better not use IRQF_TRIGGER_FALLING
when requesting the IRQ. As this can result in missing interrupts.
Further, if the device tree specified the interrupt as "IRQ_TYPE_LEVEL_LOW",
unloading and reloading of the driver results in the following error during
ifup:
| irq: type mismatch, failed to map hwirq-31 for gpio@20a8000!
| tcan4x5x spi1.1: m_can device registered (irq=0, version=32)
| tcan4x5x spi1.1 can2: TCAN4X5X successfully initialized.
| tcan4x5x spi1.1 can2: failed to request interrupt
This patch fixes the problem by removing the IRQF_TRIGGER_FALLING from the
request_threaded_irq().
Fixes: f524f829b7 ("can: m_can: Create a m_can platform framework")
Cc: Dan Murphy <dmurphy@ti.com>
Cc: Sriram Dash <sriram.dash@samsung.com>
Cc: Pankaj Sharma <pankj.sharma@samsung.com>
Link: https://lore.kernel.org/r/20201127093548.509253-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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>
The naming of can_dlc as element of struct can_frame and also as variable
name is misleading as it claims to be a 'data length CODE' but in reality
it always was a plain data length.
With the indroduction of a new 'len' element in struct can_frame we can now
remove can_dlc as name and make clear which of the former uses was a plain
length (-> 'len') or a data length code (-> 'dlc') value.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201120100444.3199-1-socketcan@hartkopp.net
[mkl: gs_usb: keep struct gs_host_frame::can_dlc as is]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
