fix(android): retry GATT subscribes dropped by GATT-busy races (1/4) - #210
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Android's GATT client allows one operation in flight; a CCCD write that races another subscribe is silently refused, leaving CAN notifications dead until reconnect. Replace the fire-and-forget descriptor write in DashKitDataSource with DashKitBleManager .subscribeWithRetry(), which verifies the write was queued and retries (up to 3x, 250ms apart). The helper is shared and will also back the Tesla status subscription.
This was referenced Aug 25, 2026
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Bottom layer of a 4-PR stacked series (the Android VIN / Tesla onboarding work above it builds on this). Also perfectly mergeable on its own.
Problem
Android's GATT client allows only one operation in flight. The CCCD (notification-enable) descriptor write that starts CAN notifications races other GATT operations during connection setup — and when it loses the race, Android silently refuses it. The old code ignored the write result entirely, so the app could sit connected with a subscribed-but-never-enabled characteristic: intermittent "connected but no dashboard data" until reconnect.
Fix
DashKitBleManager.subscribeWithRetry()— verifies the CCCD write was actually queued and retries up to 3× at 250 ms.DashKitDataSource.onServicesReady()uses it instead of the fire-and-forget inline write.The helper is deliberately generic ("CAN"/"Status" label params): the Tesla app-channel status subscription introduced later in this stack uses the same helper.
Scope discipline: 2 files, +42/−15. No behavior change beyond retry-on-refusal; no feature code.
Full
testDebugUnitTestgreen againstmain@b506147.Stack context
mainSupersedes parts of closed #201 / #206–#208 (re-layered so this fix ships independently of feature review).