VW MLB: Audi A4/S4

[jyoung8607]

Checklist

• added entry to CarInfo in selfdrive/car/*/values.py and ran selfdrive/car/docs.py to generate new docs
• test route added to routes.py
• route with openpilot:
• route with stock system:
• car harness used (if comma doesn't sell it, put N/A): VW J533

Additional Tasks

• VW MLB: Audi A4/S4 opendbc#793
• VW MLB: Audi A4/S4 panda#1289
• VW: Prep for MLB, EPS timer cleanup #27624
• upcoming PR to handle EPS timer resets
• Clean up abstractions, don't love the current structure
• Migrate to lateral accel torque controller
• Find a TSK main switch signal
• Solve issue with door-open signals
• Solve issue with gearshift position signals
• Verify BSM blocks lane changes
• Verify blinker comfort vs instantaneous

[jyoung8607]

General update: This port runs and drives quite well, it's being used by several people.

To qualify for dashcam-tier upstream support, opendbc CRC support needs to be finished and some abstractions need to be cleaned up in all three projects (opendbc, panda, openpilot). The CRC algorithm is substantially identical to MQB, but needs the usual per-message/counter data ID values calculated and added, with some MQB overlap and conflict to be resolved.

To quality for full upstream support, the remaining TODOs in this PR need to be resolved. Most notably there needs to be a mitigation for the six-minute lockout. I have agreement in principle with the openpilot team on how to do it.

The main holdup for this work is now lack of a supportable test car with supported hardware. For whatever reason, everyone that's shown up with a MLB with Adaptive Cruise has been using third-party or unsupported hardware. There are people driving with this code on C3/C3X, but none with Adaptive Cruise, so they need some mods that won't be eligible for upstream.

Anyone who has a supportable MLB with Adaptive Cruise Control, and is using a supported comma device, is welcome to contact me on Discord and I'll work with them to complete the port. This includes Porsche Macan, which should be supportable with a variant of this port.

[github-actions]

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