HCD_ERR_STALL embedded protocol_error ai_generated true

USB：主机控制器驱动队列在端点0x81上停滞，传输无法继续

USB: HCD queue stall on endpoint 0x81, transfer not progressing

ID: embedded/usb-hcd-queue-stall

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78%修复率
88%置信度
1证据数
2023-11-20首次发现

根因分析

USB主机控制器驱动在批量或控制端点上收到了设备的STALL握手信号，但驱动未清除该停滞状态，导致传输队列挂起。

English

USB host controller driver (HCD) encountered a STALL handshake from the device on a bulk or control endpoint, and the driver did not clear the stall condition, causing the transfer queue to hang.

generic

官方文档

https://www.usb.org/document-library/usb-20-specification

解决方案

  1. Send a CLEAR_FEATURE control request to the stalled endpoint. Example using STM32 HAL: HCD_EP_ClrStall(&hhcd, ep_addr); where ep_addr is the endpoint address (e.g., 0x81).
  2. Implement a recovery state machine in the USB class driver that detects stall events and automatically re-enqueues the transfer after clearing the halt.

无效尝试

常见但无效的做法:

  1. 70% 失败

    Resetting the entire USB bus without clearing the endpoint stall causes the device to re-enter the same stall state immediately.

  2. 90% 失败

    Increasing the USB transfer timeout does not resolve the stall; the device will remain stalled indefinitely.