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| -rw-r--r-- | docs/CANBUS_Troubleshooting.md | 38 |
1 files changed, 27 insertions, 11 deletions
diff --git a/docs/CANBUS_Troubleshooting.md b/docs/CANBUS_Troubleshooting.md index de0deaf7..6b7973ba 100644 --- a/docs/CANBUS_Troubleshooting.md +++ b/docs/CANBUS_Troubleshooting.md @@ -37,20 +37,36 @@ hours or more frequently) then it is an indication of a severe problem. Incrementing `bytes_invalid` on a CAN bus connection is a symptom of -reordered messages on the CAN bus. There are two known causes of -reordered messages: -1. Old versions of the popular candlight_firmware for USB CAN adapters - had a bug that could cause reordered messages. If using a USB CAN - adapter running this firmware then make sure to update to the - latest firmware if incrementing `bytes_invalid` is observed. -2. Some Linux kernel builds for embedded devices have been known to - reorder CAN bus messages. It may be necessary to use an alternative - Linux kernel or to use alternative hardware that supports - mainstream Linux kernels that do not exhibit this problem. +reordered messages on the CAN bus. If seen, make sure to: +* Use a Linux kernel version 6.6.0 or later. +* If using a USB-to-CANBUS adapter running candlelight firmware, use + v2.0 or later of candleLight_fw. +* If using Klipper's USB-to-CANBUS bridge mode, make sure the bridge + node is flashed with Klipper v0.12.0 or later. Reordered messages is a severe problem that must be fixed. It will result in unstable behavior and can lead to confusing errors at any -part of a print. +part of a print. An incrementing `bytes_invalid` is not caused by +wiring or similar hardware issues and can only be fixed by identifying +and updating the faulty software. + +Older versions of the Linux kernel had a bug in the gs_usb canbus +driver code that could cause reordered canbus packets. The issue is +thought to be fixed in +[Linux commit 24bc41b4](https://github.com/torvalds/linux/commit/24bc41b4558347672a3db61009c339b1f5692169) +which was released in v6.6.0. In some cases, older Linux versions may +not show the problem (due to how hardware interrupts are configured), +however if problems are seen the recommended solution is to upgrade to +a newer kernel. + +Older versions of candlelight firmware could reorder canbus packets, +and the issue is thought to be fixed in +[candlelight_fw commit 8b3a7b45](https://github.com/candle-usb/candleLight_fw/commit/8b3a7b4565a3c9521b762b154c94c72c5acb2bcf). + +Older versions of Klipper's USB-to-CANBUS bridge code could +incorrectly drop canbus messages. This is not as severe as reordering +messages, but it should still be fixed. It is thought to be fixed with +[Klipper PR #6175](https://github.com/Klipper3d/klipper/pull/6175). ## Use an appropriate txqueuelen setting |