USB Host stalling control transfer for Setup packet larger than max packet size

[kabas]

Hello,

I've added quite a few interfaces and endpoint configurations and I'm trying to figure out how to properly respond to "Get Descriptor" Setup packet that requires a response of size 84 bytes.

I get the  NRFX_USBD_EVT_SETUP event ,

I then send my data nrfx_usbd_ep_transfer() properly on NRFX_USBD_EPIN0, 

I get NRFX_USBD_EP_OK for the transfer and call nrfx_usbd_setup_clear(),

Then I call nrfx_usbd_ep_transfer() again with the remaining 20 bytes, and the host stalls.

I've attached the USB trace I captured as well, is there an API I'm missing to call?

[kabas]

Ah I may have figured it out, will the new nrfx APIs handle chunking the data for you? I sent greater than 64 bytes and it worked! :) 

[Jørgen Holmefjord]

Hi,

You are correct, chunking of the data is handled in nrfx. The reason for the stall looks to be that the second call to nrfx_usbd_ep_transfer() is considered a new transfer, and not a continuation of the previous one.

Best regards,
Jørgen