Deprecate 16 legacy MSP commands (for removal in INAV 10.0 or 11)

[sensei-hacker]

User description

Summary

Marks 16 legacy MSP commands as deprecated with specific replacement info, rather than immediately dropping them. This gives third-party developers (ground stations, OSD tools, telemetry apps, scripting libraries) a full major release cycle of notice before removal in INAV 10.0.

All commands remain fully functional — no behavioral changes, no code removal, no API version bump.

Supersedes

This PR supersedes the following PRs which proposed immediate removal without a deprecation period:

• Drop MSP_ANALOG frame support #9920 - Drop MSP_ANALOG frame support
• Drop MSP_MISC frame #9921 - Drop MSP_MISC frame
• Drop MSP_FILTER_CONFIG frame #9923 - Drop MSP_FILTER_CONFIG frame
• Drop MSP_OSD_CONFIG from MSP protocol #9924 - Drop MSP_OSD_CONFIG from MSP protocol
• Drop MSP_PIDNAMES #9925 - Drop MSP_PIDNAMES
• Drop MSP_SET_SERVO_MIX_RULE command #9927 - Drop MSP_SET_SERVO_MIX_RULE command
• Drop MSP_POSITION_ESTIMATION_CONFIG #9928 - Drop MSP_POSITION_ESTIMATION_CONFIG
• Drop MSP_PID_ADVANCED #9929 - Drop MSP_PID_ADVANCED

Deprecated commands and their replacements

Command	Code	Replaced by
MSP_POSITION_ESTIMATION_CONFIG	16	MSP2_COMMON_SETTING
MSP_SET_POSITION_ESTIMATION_CONFIG	17	MSP2_COMMON_SET_SETTING
MSP_OSD_CONFIG	84	MSP2_INAV_OSD_LAYOUTS / MSP2_INAV_OSD_ALARMS / MSP2_INAV_OSD_PREFERENCES
MSP_SET_OSD_CONFIG	85	MSP2_INAV_OSD_SET_LAYOUT_ITEM / MSP2_INAV_OSD_SET_ALARMS / MSP2_INAV_OSD_SET_PREFERENCES
MSP_FILTER_CONFIG	92	MSP2_COMMON_SETTING
MSP_SET_FILTER_CONFIG	93	MSP2_COMMON_SET_SETTING
MSP_PID_ADVANCED	94	MSP_INAV_PID
MSP_SET_PID_ADVANCED	95	MSP_SET_INAV_PID
MSP_ANALOG	110	MSP2_INAV_ANALOG
MSP_MISC	114	MSP2_INAV_MISC
MSP_PIDNAMES	117	No replacement needed (static data)
MSP_SET_MISC	207	MSP2_INAV_SET_MISC
MSP_SERVO_MIX_RULES	241	MSP2_INAV_SERVO_MIXER
MSP_SET_SERVO_MIX_RULE	242	MSP2_INAV_SET_SERVO_MIXER

None of these commands were previously marked as deprecated.

Changes

• src/main/msp/msp_protocol.h — Added //DEPRECATED in INAV 9.1 comments with replacement info to all 16 #defines
• docs/development/msp/msp_messages.json — Added "replaced_by" field to all 14 command entries
• docs/development/msp/format.md — Documented the new replaced_by schema field

Why deprecate instead of drop?

Third-party tools (mwptools, mobile ground stations, Lua scripts, Python libraries) may still use these commands. Dropping without notice breaks those tools silently. A deprecation cycle gives developers time to migrate, then allows clean removal in INAV 10.0.

Testing

Documentation/comment-only changes — no compiled code modified. JSON schema validated.

---

PR Type

Enhancement

---

Description

• Mark 16 legacy MSP commands as deprecated for removal in INAV 10.0

• Add deprecation comments with replacement guidance to protocol header

• Document replaced_by field in MSP message JSON schema

• Populate replaced_by field for all 14 deprecated command entries

---

Diagram Walkthrough

flowchart LR
  A["Legacy MSP Commands<br/>16 commands"] -->|Add deprecation comments| B["msp_protocol.h<br/>with replacement info"]
  A -->|Document schema field| C["format.md<br/>replaced_by field"]
  A -->|Populate metadata| D["msp_messages.json<br/>14 entries updated"]
  B --> E["Full major release cycle<br/>before removal"]
  C --> E
  D --> E

Loading

File Walkthrough

	Relevant files
Documentation	msp_protocol.h Add deprecation notices to legacy MSP command definitions src/main/msp/msp_protocol.h Added //DEPRECATED in INAV 9.1 comments to 16 MSP command #define statements Included specific replacement command names or guidance for each deprecated command Commands affected: MSP_POSITION_ESTIMATION_CONFIG (16), MSP_SET_POSITION_ESTIMATION_CONFIG (17), MSP_OSD_CONFIG (84), MSP_SET_OSD_CONFIG (85), MSP_FILTER_CONFIG (92), MSP_SET_FILTER_CONFIG (93), MSP_PID_ADVANCED (94), MSP_SET_PID_ADVANCED (95), MSP_ANALOG (110), MSP_MISC (114), MSP_PIDNAMES (117), MSP_SET_MISC (207), MSP_SERVO_MIX_RULES (241), MSP_SET_SERVO_MIX_RULE (242) No functional code changes, only documentation comments +14/-14  format.md Document replaced_by schema field for deprecated commands docs/development/msp/format.md Added documentation for new replaced_by schema field in MSP message format Defined as optional array of MSP message names that replace deprecated commands Clarified that empty array indicates no replacement is needed +1/-0
Configuration changes	msp_messages.json Populate replaced_by metadata for deprecated MSP commands docs/development/msp/msp_messages.json Added replaced_by field to 14 deprecated MSP command entries in JSON schema MSP_POSITION_ESTIMATION_CONFIG (16) → ["MSP2_COMMON_SETTING"] MSP_SET_POSITION_ESTIMATION_CONFIG (17) → ["MSP2_COMMON_SET_SETTING"] MSP_OSD_CONFIG (84) → ["MSP2_INAV_OSD_LAYOUTS", "MSP2_INAV_OSD_ALARMS", "MSP2_INAV_OSD_PREFERENCES"] MSP_SET_OSD_CONFIG (85) → ["MSP2_INAV_OSD_SET_LAYOUT_ITEM", "MSP2_INAV_OSD_SET_ALARMS", "MSP2_INAV_OSD_SET_PREFERENCES"] MSP_FILTER_CONFIG (92) → ["MSP2_COMMON_SETTING"] MSP_SET_FILTER_CONFIG (93) → ["MSP2_COMMON_SET_SETTING"] MSP_PID_ADVANCED (94) → ["MSP_INAV_PID"] MSP_SET_PID_ADVANCED (95) → ["MSP_SET_INAV_PID"] MSP_ANALOG (110) → ["MSP2_INAV_ANALOG"] MSP_MISC (114) → ["MSP2_INAV_MISC"] MSP_PIDNAMES (117) → [] (no replacement needed) MSP_SET_MISC (207) → ["MSP2_INAV_SET_MISC"] MSP_SERVO_MIX_RULES (241) → ["MSP2_INAV_SERVO_MIXER"] MSP_SET_SERVO_MIX_RULE (242) → ["MSP2_INAV_SET_SERVO_MIXER"] +14/-0

---

[qodo-code-review]

PR Compliance Guide 🔍

All compliance sections have been disabled in the configurations.

[sensei-hacker]

@xznhj8129 Does this addition to the JSON work for you?

[xznhj8129]

@xznhj8129 Does this addition to the JSON work for you?

Yes that looks like a solid addition, will make it easier to parse rather than just a note

[stronnag]

If you really think this is worth doing, by the same logic, you might consider deprecating other obsolete messages superseded by MSP2_INAV_STATUS, e.g.:

• MSP_STATUS
• MSP_STATUS_EX

and MSP_DEBUG (superseded by MSP2_INAV_DEBUG).

and MSP_SET_BLACKBOX_CONFIG (superseded by MSP2_SET_BLACKBOX_CONFIG, #4302)

and probably the others listed as "Superseded" in the MSP reference.

Also

• Bump MSP API_VERSION_MINOR

[sensei-hacker]

Bump MSP API_VERSION_MINOR

Should we bump the version number when we aren't adding or removing anything other than a comment? I don't mind doing so, just checking. Or should that wait until we actually change the implementation, when something is removed in INAV 10 or 11?

If you really think this is worth doing, by the same logic

What do you think? This was initiated by Pawel and I was somewhat figuring "if Pawel think it should be done, maybe it should be". I also value your opinion.