| # Copyright (c) 2010 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. |
| import logging |
| |
| from autotest_lib.client.bin import test |
| from autotest_lib.client.common_lib import error |
| from autotest_lib.client.cros import service_stopper |
| from autotest_lib.client.cros.power import power_utils |
| |
| |
| class hardware_Backlight(test.test): |
| version = 1 |
| |
| def initialize(self): |
| """Perform necessary initialization prior to test run. |
| |
| Private Attributes: |
| _backlight: power_utils.Backlight object |
| _services: service_stopper.ServiceStopper object |
| """ |
| super(hardware_Backlight, self).initialize() |
| self._backlight = None |
| # Stop powerd to avoid it adjusting backlight levels |
| self._services = service_stopper.ServiceStopper(['powerd']) |
| self._services.stop_services() |
| |
| |
| def run_once(self): |
| # optionally test keyboard backlight |
| kblight = None |
| kblight_errs = 0 |
| try: |
| kblight = power_utils.KbdBacklight() |
| except power_utils.KbdBacklightException as e: |
| logging.info("Assuming no keyboard backlight due to %s", str(e)) |
| |
| if kblight: |
| init_percent = kblight.get_percent() |
| try: |
| for i in xrange(100, -1, -1): |
| kblight.set_percent(i) |
| result = int(kblight.get_percent()) |
| if i != result: |
| logging.error('keyboard backlight set %d != %d get', |
| i, result) |
| kblight_errs += 1 |
| finally: |
| kblight.set_percent(init_percent) |
| |
| if kblight_errs: |
| raise error.TestFail("%d errors testing keyboard backlight." % \ |
| kblight_errs) |
| |
| self._backlight = power_utils.Backlight() |
| backlight_errs = 0 |
| backlight_max = self._backlight.get_max_level() |
| for i in xrange(backlight_max + 1): |
| self._backlight.set_level(i) |
| result = self._backlight.get_level() |
| if i != result: |
| # The kernel Documentation/ABI/stable/sysfs-class-backlight |
| # states that the requested brightness may not be the |
| # actual_brightness. |
| # Although not specified in the docs, let's allow the difference |
| # between requested brightness and actual_brightness percent be |
| # within a tolerance of 1 of each other. |
| actual_percent = self._backlight.get_percent() |
| expected_percent = float(i) / float(backlight_max) * 100.0 |
| diff_percent = abs(actual_percent - expected_percent) |
| log_level_func = logging.warn |
| if diff_percent > 1: |
| backlight_errs += 1 |
| log_level_func = logging.error |
| log_level_func('backlight expected vs. actual exceeds error' |
| 'tolerance') |
| log_level_func('backlight set %d != %d get', i, result) |
| log_level_func('backlight percent difference is %f%%', |
| diff_percent) |
| |
| if backlight_errs: |
| raise error.TestFail("%d errors testing backlight." % \ |
| backlight_errs) |
| |
| |
| def cleanup(self): |
| if self._backlight: |
| self._backlight.restore() |
| self._services.restore_services() |
| super(hardware_Backlight, self).cleanup() |
