[RFC PATCH v3 0/6] Add helpers for stats and error frames

[Dario Binacchi]

This series originates from some tests I ran on a CAN communication for
one of my clients that reports sporadic errors. After enabling BERR
reporting, I was surprised that the command:

ip -details -statistics link show can0

did not display the occurrence of different types of errors, but only the
generic ones for reception and transmission. In trying to export this
information, I felt that the code related to managing statistics and handling
CAN errors (CRC, STUF, BIT, ACK, and FORM) was quite duplicated in the
implementation of various drivers, and there wasn't a generic function like
in the case of state changes (i. e. can_change_state). This led to the idea
of adding can_update_bus_error_stats() and the helpers for setting up the
CAN error frame.

Regarding patch 5/6 ("can: netlink: extend stats to the error types (ack,
CRC, form, ..."), I ran

./scripts/check-uapi.sh

which found

"error - 1/934 UAPI headers compatible with x86 appear _not_ to be backwards
compatible."

I included it in the series because I am currently interested in understanding
whether the idea behind each of the submitted patches makes sense, and I can
adjust them later if the response is positive, following your suggestions.

Changes in v3:
- Drop double assignement of "priv" variable.
- Check "dev" parameter is not NULL.
- Drop the check of "cf" parameter not NULL

Changes in v2:
- Replace macros with static inline functions
- Update the commit message
- Replace the macros with static inline funcions calls.
- Update the commit message

Dario Binacchi (6):
  can: dev: add generic function can_update_bus_error_stats()
  can: flexcan: use can_update_bus_error_stats()
  can: dev: add helpers to setup an error frame
  can: flexcan: use helpers to setup the error frame
  can: netlink: extend stats to the error types (ack, CRC, form, ...)
  can: dev: update the error types stats (ack, CRC, form, ...)

 drivers/net/can/dev/dev.c              | 45 ++++++++++++++++++++++++++
 drivers/net/can/flexcan/flexcan-core.c | 29 +++++------------
 include/linux/can/dev.h                | 38 ++++++++++++++++++++++
 include/uapi/linux/can/netlink.h       |  6 ++++
 4 files changed, 97 insertions(+), 21 deletions(-)

-- 
2.43.0