93e5dfa59b
IRQ latency can be ridiculously high for various reasons, so our current timeouts of 100 ms or 10 ms are too short. Change the IRQ and event tests to use polling loops starting with a delay of 1 tick and doubling that if necessary up to a maximum total delay of approximately 1 second. Raise the loopback packet RX timeout to 1 second. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>