Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox
The flexcan IP core on the MCF5441X cannot receive CAN RTR messages
via mailboxes. However the mailbox mode is more performant. The commit
| 1c45f5778a ("can: flexcan: add ethtool support to change rx-rtr setting during runtime")
added support to switch from FIFO to mailbox mode on these cores.
After testing the mailbox mode on the MCF5441X by Angelo Dureghello,
this patch marks it (without RTR capability) as supported. Further the
IP core overview table is updated, that RTR reception via mailboxes is
not supported.
Link: https://lore.kernel.org/all/20220121084425.3141218-1-mkl@pengutronix.de
Tested-by: Angelo Dureghello <angelo@kernel-space.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch adds a private flag to the flexcan driver to switch the
"rx-rtr" setting on and off.
"rx-rtr" on - Receive RTR frames. (default)
The CAN controller can and will receive RTR frames.
On some IP cores the controller cannot receive RTR
frames in the more performant "RX mailbox" mode and
will use "RX FIFO" mode instead.
"rx-rtr" off - Waive ability to receive RTR frames. (not supported on all IP cores)
This mode activates the "RX mailbox mode" for better
performance, on some IP cores RTR frames cannot be
received anymore.
The "RX FIFO" mode uses a FIFO with a depth of 6 CAN frames.
The "RX mailbox" mode uses up to 62 mailboxes.
Link: https://lore.kernel.org/all/20220107193105.1699523-6-mkl@pengutronix.de
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Co-developed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
