tree 992c3bb64ac3a1cd07f725b653bb91e84585d6af
parent f1a0ed905b6056f187c0130086faa4e088a9c47b
author Harald Welte <laforge@osmocom.org> 1579213248 +0100
committer Harald Welte <laforge@osmocom.org> 1646330772 +0100

HACK: Solve weird problem with lost OUT transfer on ping-pong endpoint

This adds an unconditional endpoint reset procedure to every SET_FEATURE(UnHalt).

It doesn't really make sense that this is required, *particularly* as
we *MUST NOT* set bEndpoint->bank to 0 here.

Without this patch, I'm observing the following problem:

Every first OUT transfer after a SET_INTERFACE + UNHALT on a bulk endpoint
is lost. "lost" means that it completes successfully on the host, can
be seen completing successfully with an ACK on a USB bus analyzer,
but still doesn't show up in the firmware.  No Endpoint Interrupt
is generated.

This can be reproduced by calling libusb_set_interface_alt_setting()
from the host and then submitting a single OUT transfer.

Change-Id: I18ed530e617baddf76e8f9829512443ce2a76e0d