Trouble loading firmware to USB device

Hi all,

I am trying to load the copy the OpenBSD athn code. Currently I am
trying to load the firmware of the device but running an issue where
the interrupt RX callback is getting an USB_ERR_CANCELLED event.

Based on my reading of the OpenBSD code, it appears that the OpenBSD
driver will load the firmware in chunks, then submit a NULL (size 0)
usbd_do_request to indicate completion of the firmware. At this, the
driver will tsleep() for 1 second. If it breaks with a return value of
0, the driver will continue successfully. My understanding is that this
should trigger an Rx Interrupt, which should run the wakup() that the
tsleep() is looking for.

However, in my case the USB_ST_SETUP condition is run, but it seems to
block indefinitely. Meanwhile, the tsleep() expires, returns a
EWOULDBLOCK and eventually runs the detach handler. As a result, the
blocking callback receives a USB_ST_ERROR with the value
USB_ERR_CANCELLED.

What might be causing the blocking of the callback? Am I loading the
firmware incorrectly?

My firmware code is here:
https://github.com/khanzf/freebsd/blob/ar9271-check/sys/dev/athn/usb/if_athn_usb.c#L934
The interrupt handler, athn_usb_intr, is line 2405.

The OpenBSD equivalent of the firmware loader is this:
https://github.com/openbsd/src/blob/master/sys/dev/usb/if_athn_usb.c#L642
The interrupt handler is also athn_usb_intr online 1874.

Any assistance would be great, been stuck for a few weeks :/

--
Farhan Khan
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