| # Copyright 2011 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| # |
| # Check timers behavior |
| # |
| |
| import time |
| |
| def one_pass(helper): |
| helper.wait_output("=== Timer calibration ===") |
| res = helper.wait_output("back-to-back get_time : (?P<lat>[0-9]+) us", |
| use_re=True)["lat"] |
| minlat = int(res) |
| helper.trace("get_time latency %d us\n" % minlat) |
| |
| helper.wait_output("sleep 1s") |
| t0 = time.time() |
| second = helper.wait_output("done. delay = (?P<second>[0-9]+) us", |
| use_re=True)["second"] |
| t1 = time.time() |
| secondreal = t1 - t0 |
| secondlat = int(second) - 1000000 |
| helper.trace("1s timer latency %d us / real time %f s\n" % (secondlat, |
| secondreal)) |
| |
| |
| us = {} |
| for pow2 in range(7): |
| delay = 1 << (7-pow2) |
| us[delay] = helper.wait_output("%d us => (?P<us>[0-9]+) us" % delay, |
| use_re=True)["us"] |
| helper.wait_output("Done.") |
| |
| return minlat, secondlat, secondreal |
| |
| |
| def test(helper): |
| one_pass(helper) |
| |
| helper.ec_command("reboot") |
| helper.wait_output("--- UART initialized") |
| |
| # get the timing results on the second pass |
| # to avoid binary translation overhead |
| minlat, secondlat, secondreal = one_pass(helper) |
| |
| # check that the timings somewhat make sense |
| if minlat > 220 or secondlat > 500 or abs(secondreal-1.0) > 0.200: |
| helper.fail("imprecise timings " + |
| "(get_time %d us sleep %d us / real time %.3f s)" % |
| (minlat, secondlat, secondreal)) |
| |
| return True # PASS ! |
