linux-stable.git/drivers/net/can/dev, branch v5.19.2

can: netlink: allow configuring of fixed data bit rates without need for do_set_data_bittiming callback

2022-08-17T13:14:29+00:00

[ Upstream commit ec30c109391c5eac9b1d689a61e4bfed88148947 ]

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 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: netlink: allow configuring of fixed bit rates without need for do_set_bittiming callback

2022-08-17T13:14:29+00:00

[ Upstream commit 7e193a42c37cf40eba8ac5af2d5e8eeb8b9506f9 ]

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 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: can-dev: remove obsolete CAN LED support

2022-05-19T20:15:51+00:00

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 
Signed-off-by: Oliver Hartkopp 
[mkl: remove led.h from MAINTAINERS]
Signed-off-by: Marc Kleine-Budde

can: can-dev: move to netif_napi_add_weight()

2022-05-19T20:11:28+00:00

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 
Signed-off-by: Marc Kleine-Budde

can: bittiming: can_calc_bittiming(): prefer small bit rate pre-scalers over larger ones

2022-04-19T15:12:05+00:00

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 
Signed-off-by: Marc Kleine-Budde

can: rx-offload: rename can_rx_offload_queue_sorted() -> can_rx_offload_queue_timestamp()

2022-04-19T14:58:04+00:00

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

can: Use netif_rx().

2022-03-06T11:05:31+00:00

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 
Cc: Oliver Hartkopp 
Cc: Wolfgang Grandegger 
Cc: linux-can@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior 
Acked-by: Oliver Hartkopp 
Acked-by: Marc Kleine-Budde 
Signed-off-by: David S. Miller

can: bittiming: mark function arguments and local variables as const

2022-02-24T07:26:03+00:00

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

can: bittiming: can_validate_bitrate(): simplify bit rate checking

2022-02-24T07:26:03+00:00

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

can: netlink: report the CAN controller mode supported flags

2022-01-05T11:09:06+00:00

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 
Signed-off-by: Marc Kleine-Budde