[PATCH v2 00/27] can: at91: add can_state_get_by_berr_counter() helper, cleanup and convert to rx_offload

[Marc Kleine-Budde <mkl@pengutronix.de>]

This series first introduces the can_state_get_by_berr_counter()
helper function. It returns the current TX and RX state depending on
the provided CAN bit error counters. It will be later used by the
at91_can driver.

The remaining patches of this series first clean up the at91_can
driver, clean up the bus- and line error (including bus-off) handling,
and then convert it use the rx_offload helper. The driver works better
under high system load and the order of received CAN frames is better
maintained.

Due to a hardware limitation the converted driver could trigger a race
condition in the can_restart() CAN bus-off handler. The patch series
[1] fixes the issue.

[1] https://lore.kernel.org/all/20231004-can-dev-fix-can-restart-v1-0-2e52899eaaf5@pengutronix.de

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
Changes in v2:
- 1/27: can_state_err_to_state(): use symbolic error values instead of
  plain numbers (Thanks Vincent)
- 27/27: fix patch description and typos (Thanks Vincent)
- Link to v1: https://lore.kernel.org/all/20231004-at91_can-rx_offload-v1-0-c32bf99097db@pengutronix.de

---
Marc Kleine-Budde (27):
      can: dev: add can_state_get_by_berr_counter() to return the CAN state based on the current error counters
      can: at91_can: use a consistent indention
      can: at91_can: at91_irq_tx(): remove one level of indention
      can: at91_can: BR register: convert to FIELD_PREP()
      can: at91_can: ECR register: convert to FIELD_GET()
      can: at91_can: MMR registers: convert to FIELD_PREP()
      can: at91_can: MID registers: convert access to FIELD_PREP(), FIELD_GET()
      can: at91_can: MSR Register: convert to FIELD_PREP()
      can: at91_can: MCR Register: convert to FIELD_PREP()
      can: at91_can: add more register definitions
      can: at91_can: at91_setup_mailboxes(): update comments
      can: at91_can: rename struct at91_priv::{tx_next,tx_echo} to {tx_head,tx_tail}
      can: at91_can: at91_set_bittiming(): demote register output to debug level
      can: at91_can: at91_chip_start(): don't disable IRQs twice
      can: at91_can: at91_open(): forward request_irq()'s return value in case or an error
      can: at91_can: add CAN transceiver support
      can: at91_can: at91_poll_err(): fold in at91_poll_err_frame()
      can: at91_can: at91_poll_err(): increase stats even if no quota left or OOM
      can: at91_can: at91_irq_err_frame(): call directly from IRQ handler
      can: at91_can: at91_irq_err_frame(): move next to at91_irq_err()
      can: at91_can: at91_irq_err(): rename to at91_irq_err_line()
      can: at91_can: at91_irq_err_line(): make use of can_state_get_by_berr_counter()
      can: at91_can: at91_irq_err_line(): take reg_sr into account for bus off
      can: at91_can: at91_irq_err_line(): make use of can_change_state() and can_bus_off()
      can: at91_can: at91_irq_err_line(): send error counters with state change
      can: at91_can: at91_alloc_can_err_skb() introduce new function
      can: at91_can: switch to rx-offload implementation

 drivers/net/can/Kconfig    |   1 +
 drivers/net/can/at91_can.c | 998 ++++++++++++++++++---------------------------
 drivers/net/can/dev/dev.c  |  22 +
 include/linux/can/dev.h    |   4 +
 4 files changed, 432 insertions(+), 593 deletions(-)
---
base-commit: 93e7eca853ca0087b129433630ddd89288d2b8b4
change-id: 20231004-at91_can-rx_offload-32628a740af2

Best regards,
-- 
Marc Kleine-Budde <mkl@pengutronix.de>