endpoint will mistakenly enter stall state while sending descritor

eclipse-threadx / usbx

Eclipse ThreadX - USBX is a high-performance USB host, device, and on-the-go (OTG) embedded stack, that is fully integrated with Eclipse ThreadX RTOS

https://github.com/eclipse-threadx/rtos-docs/blob/main/rtos-docs/usbx/index.md

MIT License

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endpoint will mistakenly enter stall state while sending descritor #94

Closed xuzihan351 closed 1 year ago

xuzihan351 commented 1 year ago

ux_device_stack_descriptor_send:+404

  /* Ensure we have the correct language page.  */
  if (_ux_utility_short_get(string_framework) == request_index)

In some cases, host will send GET_STRING_DESCRTIPTOR setup packet with wIndex(the request_index var) == 0x0000, because of the code before, the stack will not be able to find a valid string and will generate a endpoint stall.

USBX version: 6.2.1
THREADX version: 6.2.1

xiaocq2001 commented 1 year ago

As described in USB spec,

Zero wIndex case is not for string descriptor (reset to zero for other descriptors), we need to consider if it should be implemented.