In mcp251xfd_register_get_dev_id() the device ID register is read with
handcrafted SPI transfers. As all registers, this register is in
little endian. Further it is not naturally aligned in struct
mcp251xfd_map_buf_nocrc::data. However after the transfer the register
content is converted from big endian to CPU endianness not taking care
of being unaligned.
Fix the conversion by converting from little endian to CPU endianness
taking the unaligned source into account.
Side note: So far the register content is 0x0 on all mcp251xfd
compatible chips, and is only used for an informative printk.
Link: https://lore.kernel.org/all/20220627092859.809042-1-mkl@pengutronix.de
Fixes: 55e5b97f00 ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN")
Reviewed-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The device ID register is 32 bits wide. The driver uses incorrectly
the size of a pointer to a u32 to calculate the length of the SPI
transfer. This results in a read of 2 registers on 64 bit platforms.
This is no problem on the Linux side, as the RX buffer of the SPI
transfer is large enough. In the mpc251xfd chip this results in the
read of an undocumented register. So far no problems were observed.
Fix the length of the SPI transfer to read the device ID register
only.
Link: https://lore.kernel.org/all/20220616094914.244440-1-mkl@pengutronix.de
Fixes: 55e5b97f00 ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN")
Reported-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
In commit 169d00a256 ("can: mcp251xfd: add TX IRQ coalescing
support") software based TX coalescing was added to the driver. The
key idea is to keep the TX complete IRQ disabled for some time after
processing it and re-enable later by a hrtimer. When bringing the
interface down, this timer has to be stopped.
Add the missing hrtimer_cancel() of the tx_irq_time hrtimer to
mcp251xfd_stop().
Link: https://lore.kernel.org/all/20220620143942.891811-1-mkl@pengutronix.de
Fixes: 169d00a256 ("can: mcp251xfd: add TX IRQ coalescing support")
Cc: stable@vger.kernel.org # v5.18
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Clang static analysis reports this issue:
| mcp251xfd-core.c:1813:7: warning: The left operand
| of '&' is a garbage value
| FIELD_GET(MCP251XFD_REG_DEVID_ID_MASK, dev_id),
| ^ ~~~~~~
dev_id is set in a successful call to mcp251xfd_register_get_dev_id().
Though the status of calls made by mcp251xfd_register_get_dev_id() are
checked and handled, their status' are not returned. So return err.
Fixes: 55e5b97f00 ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN")
Link: https://lore.kernel.org/all/20220319153128.2164120-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch adds RX IRQ coalescing support to the driver.
The mcp251xfd chip doesn't support proper hardware based coalescing,
so this patch tries to implemented it in software. The RX-FIFO offers
a "FIFO not empty" interrupt, which is used if no coalescing is
active.
With activated RX IRQ coalescing the "FIFO not empty" interrupt is
disabled in the RX IRQ handler and the "FIFO half full" or "FIFO full
interrupt" (depending on RX max coalesced frames IRQ) is used instead.
To avoid RX CAN frame starvation a hrtimer is setup with RX coalesce
usecs IRQ,on timer expiration the "FIFO not empty" is enabled again.
Support for ethtool configuration is added in the next patch.
Link: https://lore.kernel.org/20220313083640.501791-9-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Mark Brown says:
====================
spi: Make remove() return void
This series from Uwe Kleine-König converts the spi remove function to
return void since there is nothing useful that we can do with a failure
and it as more buses are converted it'll enable further work on the
driver core.
====================
Link: https://lore.kernel.org/r/20220228173957.1262628-2-broonie@kernel.org/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch prepares the driver to use more than one RX-FIFO. Having a
bigger RX buffer is beneficial in high load situations, where the
system temporarily cannot keep up reading CAN frames from the chip.
Using a bigger RX buffer also allows to implement RX IRQ coalescing,
which will be added in a later patch series.
If using more than 1 RX-FIFO the driver has to figure out, which FIFOs
have RX'ed CAN frames pending. This is indicated by a set bit in the
RXIF register, which is positioned directly after the interrupt status
register INT. If more than 1 RX-FIFO is used, the driver reads both
registers in 1 transfer.
The mcp251xfd_handle_rxif() function iterates over all RX rings and
reads out the RX'ed CAN frames for for all pending FIFOs. To keep the
logic for the 1 RX-FIFO only case in mcp251xfd_handle_rxif() simple,
the driver marks that FIFO pending in mcp251xfd_ring_init().
The chip has a dedicated RX interrupt line to signal pending RX'ed
frames. If connected to an input GPIO and the driver will skip the
initial read of the interrupt status register (INT) and directly read
the pending RX'ed frames if the line is active. The driver assumes the
1st RX-FIFO pending (a read of the RXIF register would re-introduce
the skipped initial read of the INT register). Any other pending
RX-FIFO will be served in the main interrupt handler.
Link: https://lore.kernel.org/all/20220217103826.2299157-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
With this patch the usage of the on-chip RAM is checked. In the
current driver the FIFO setup is fixed and always fits into the RAM.
With an upcoming patch series the ring and FIFO setup will be more
dynamic. Although using more RAM than available should not happen, but
add this safety check, just in case.
Link: https://lore.kernel.org/all/20220217103826.2299157-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch prepares the mcp251xfd_chip_clock_init() function for PLL
support.
If the PLL is needed is must be switched on after chip reset. This
should be done in the mcp251xfd_chip_clock_init() function. Prepare
this function to wait for the OSC and PLL to be ready.
Link: https://lore.kernel.org/all/20220207131047.282110-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch changes the order of reading the Mode and Oscillator Ready
bits.
Instead of reading the Mode of the chip directly after reset, first
wait for the oscillator to get ready and the chip to fully start up.
Read the Mode after this.
Link: https://lore.kernel.org/all/20220207131047.282110-10-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The function mcp251xfd_chip_wait_for_osc_ready() polls the Oscillator
Control Register for the oscillator to get ready. By passing the
appropriate parameters (osc_reference and osc_mask) it can also poll
for PLL ready.
This patch adjusts the error message if the Oscillator and/or PLL fail
to get ready.
Link: https://lore.kernel.org/all/20220207131047.282110-9-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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>
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 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>
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>
