Re [PATCH v3 0/2] usb: offload: Decouple interrupter lifecycle and refactor usage tracking

[hailong]

Hi,
We, OPPO kernel team, have thoroughly verified this patch on our devices.
The test results confirm that it effectively resolves a critical headset
hot-plugging issue and the subsequent system deadlock.

Impact:
This issue is currently a blocker for our upcoming product shipping.
We have observed a high reproduction rate on our latest platforms,
and this patch is essential for our production stability.

Test Environment:
Devices: OPPO devices based on SM8850 and SM8845 platforms.
OS/Kernel: Android 16.0 / Linux Kernel 6.12.

Background:
High reproduction rate (typically within 10 cycles) before
applying this patch.

Original Reproduction Path (Verified fixed):
Open music player and enable USB exclusive mode.
Connect a Type-C digital headset and start playback.
Repeatedly plug/unplug the headset.

Observation:
Within 10 cycles, the headset icon would persist after
unplugging, followed by no audio upon reconnection and a system deadlock.

Stress Test Results with This Patch (Phone A & B):
Test Case 1: USB Exclusive Mode Hot-plug
Steps: Enable USB exclusive mode -> Play music -> Plug/unplug 100 cycles.
Result: PASS. Audio functions normally; no deadlock observed.

Test Case 2: Standard Mode Hot-plug
Steps: Disable USB exclusive mode -> Play music -> Plug/unplug 100 cycles.
Result: PASS. Audio and system stability remain normal.

Test Case 3: Mixed Accessory Switching (Headset/Charger)
Steps: Play music -> Unplug headset -> Plug in charger -> Unplug charger
-> Re-plug headset. Repeated for 30 cycles.
Result: PASS. No issues observed.

The patch looks solid and is critical for our project. We hope these
results help expedite the upstreaming process.

Free to add
Tested-by: hailong.liu@xxxxxxxx