Revert "can: m_can: pci: use custom bit timings for Elkhart Lake"
authorJarkko Nikula <jarkko.nikula@linux.intel.com>
Thu, 12 May 2022 12:41:43 +0000 (15:41 +0300)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Sat, 14 May 2022 18:49:09 +0000 (20:49 +0200)
commit14ea4a470494528c7e88da5c4116c24eb027059f
tree68a5ba260ca0cb0b30f4c768bffdc9f227956267
parentf3f19f939c11925dadd3f4776f99f8c278a7017b
Revert "can: m_can: pci: use custom bit timings for Elkhart Lake"

This reverts commit 0e8ffdf3b86dfd44b651f91b12fcae76c25c453b.

Commit 0e8ffdf3b86d ("can: m_can: pci: use custom bit timings for
Elkhart Lake") broke the test case using bitrate switching.

| ip link set can0 up type can bitrate 500000 dbitrate 4000000 fd on
| ip link set can1 up type can bitrate 500000 dbitrate 4000000 fd on
| candump can0 &
| cangen can1 -I 0x800 -L 64 -e -fb \
|     -D 11223344deadbeef55667788feedf00daabbccdd44332211 -n 1 -v -v

Above commit does everything correctly according to the datasheet.
However datasheet wasn't correct.

I got confirmation from hardware engineers that the actual CAN
hardware on Intel Elkhart Lake is based on M_CAN version v3.2.0.
Datasheet was mirroring values from an another specification which was
based on earlier M_CAN version leading to wrong bit timings.

Therefore revert the commit and switch back to common bit timings.

Fixes: ea4c1787685d ("can: m_can: pci: use custom bit timings for Elkhart Lake")
Link: https://lore.kernel.org/all/20220512124144.536850-1-jarkko.nikula@linux.intel.com
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reported-by: Chee Hou Ong <chee.houx.ong@intel.com>
Reported-by: Aman Kumar <aman.kumar@intel.com>
Reported-by: Pallavi Kumari <kumari.pallavi@intel.com>
Cc: <stable@vger.kernel.org> # v5.16+
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
drivers/net/can/m_can/m_can_pci.c