jpmschweitzerandClaude Fable 5
cb5826e02b
Root cause (verified against our exact IDF tree, not the community guess): the "258" in "sdio_write_task: Failed to send data: 258" is NOT a timeout (that is 263). 258 = 0x102 = ESP_ERR_INVALID_ARG. On the ESP32-P4, block- mode CMD53 writes require the SOURCE buffer to be 64-byte (cache-line) aligned; the IDF sdmmc driver rejects a misaligned source with INVALID_ARG BEFORE any bus activity. esp_hosts write loop then declares "Unrecoverable host sdio state" and reboots the whole P4. The audio TX payload is not 64-aligned, so streaming mic audio wedged on the very FIRST frame (which is exactly what we saw: listening -> instant Failed to send -> reboot). This also explains why buffer/queue/clock/retry tuning all did nothing: the write never reached the bus. And why our symptom was instant, not after ~100 writes (the community block-mode-desync theory) — it is the first misaligned buffer, every time. Fix: vendored esp_hosted 2.12.11 as an editable local component (overrides the registry copy) and bounce a misaligned TX payload through one aligned DMA scratch buffer in hosted_sdio_write_block (port_esp_hosted_host_sdio.c). TX is serialized by the bus lock so a single static bounce buffer is safe; freed in hosted_sdio_deinit. Host-only change — no C6 reflash. VERIFIED ON HARDWARE (autonomous self-test): 40s of continuous mic-audio upstream streaming — the traffic that previously wedged on the first frame — ran clean, zero timeouts, zero reboots. A guarded SDIO_TX_SELFTEST harness is kept (compiled out) for future SDIO stress testing. Credit: root cause + patch designed via multi-agent investigation; the precise 258=INVALID_ARG decode (correcting the upstream community timeout assumption) came from checking our actual esp_err.h. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
3.6 KiB
3.6 KiB
Shield Box Test Setup for ESP-Hosted
Controlled RF environment for consistent throughput measurements and performance evaluation.
Overview
Shield Box Testing uses RF-shielded enclosure to eliminate external interference and provide repeatable test conditions.
Key Benefits:
- Controlled RF environment (no external Wi-Fi/cellular interference)
- Repeatable, consistent results
- Better measurement accuracy vs open air
Equipment Required
Essential Components
- RF Shield Box/Chamber: Faraday cage enclosure
- ESP32-P4 Function EV Board: Host device
- ESP32-C6/C5 Test Board: Co-processor device
- External PC: For iPerf client/server
- Router/Access Point: Wi-Fi infrastructure
- Ethernet Connection: Wired backhaul to PC
Please change the host and co-processor nodes as per current use-case under test.
Test Setup
Physical Configuration
flowchart TB
%% floating IP labels — above their boxes, faint leader line
ipAP["192.168.1.1"]:::ip
ipP4["192.168.1.2"]:::ip
ipHost["192.168.1.88 · test<br/>10.0.0.1 · control"]:::ip
ipDev["10.0.0.2"]:::ip
subgraph SB["Shield Box"]
AP["📶 AP / Router"]
subgraph EVB["ESP32-P4-Function-EV-Board 1.2+"]
direction LR
C6["ESP32-C6<br/>Wi-Fi slave"]
P4["ESP32-P4<br/>iperf app"]
C6 ---|"SDIO"| P4
end
AP -.-|"Wi-Fi"| C6
HOST["AP-backend<br/>iperf host"]
AP ===|"LAN cable"| HOST
P4 ---|"USB / UART"| HOST
end
DEV["Dev machine"]
HOST ---|"control"| DEV
%% faint leaders from IP labels to devices
ipAP -.- AP
ipP4 -.- P4
ipHost -.- HOST
ipDev -.- DEV
style SB fill:#fff7ec,stroke:#e8a33d,color:#333
style EVB fill:#efeaf8,stroke:#8a7bbd,color:#333
classDef node fill:#ffffff,stroke:#99aabb,color:#111
classDef ip fill:none,stroke:none,color:#555
class AP,C6,P4,HOST,DEV node
linkStyle 0 stroke:#e8762d,stroke-width:2.5px
linkStyle 1 stroke:#e8762d,stroke-width:2.5px
linkStyle 2 stroke:#e8762d,stroke-width:2.5px
linkStyle 3 stroke:#888888,stroke-width:1.5px,stroke-dasharray:5
linkStyle 4 stroke:#0e9488,stroke-width:2px
linkStyle 5 stroke:#cccccc,stroke-width:1px,stroke-dasharray:2 2
linkStyle 6 stroke:#cccccc,stroke-width:1px,stroke-dasharray:2 2
linkStyle 7 stroke:#cccccc,stroke-width:1px,stroke-dasharray:2 2
linkStyle 8 stroke:#cccccc,stroke-width:1px,stroke-dasharray:2 2
Data Flow
- PC to MCU Host:
PC -> Router -> ESP Co-processor == SDIO/SPI/UART ==> ESP32-P4 - MCU Host to PC:
PC <- Router <- ESP Co-processor <== SDIO/SPI/UART == ESP32-P4
Traffic route:
- PC-to-Router: Ethernet with static IP (eliminates wireless variables)
- Router-to-ESP: Wi-Fi connection (only wireless link in test chain)
Transport Configurations
SDIO (Highest Performance)
- Clock: 20-50 MHz (start low, optimize up)
- Bus Width: 4-bit mode
- Hardware: External pull-ups (51kΩ) on CMD, D0-D3
SPI
- Clock: ESP32: ≤10 MHz, Others: ≤40 MHz
- Mode: Full-duplex (simple) or Quad SPI (highest throughput)
UART
- Baud Rate: 921600 (highest stable rate)
- Use Case: Low-throughput validation, debugging
Shield Box vs Open Air
| Aspect | Shield Box | Open Air |
|---|---|---|
| Repeatability | High | Variable |
| Interference | Eliminated | Present |
| Debugging | Easier | Complex |
| Reality | Lower | Higher |
For transport setup details: SDIO | SPI Full-Duplex | SPI Half-Duplex | UART