| # Copyright (c) 2012 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, time |
| from autotest_lib.client.bin import test, utils |
| from autotest_lib.client.common_lib import error |
| from autotest_lib.client.cros.graphics import graphics_utils |
| from autotest_lib.client.cros.power import power_status, power_utils |
| |
| |
| def get_num_outputs_on(): |
| """ |
| Retrieves the number of connected outputs that are on. |
| @return: integer value of number of connected outputs that are on. |
| """ |
| |
| return graphics_utils.get_num_outputs_on(); |
| |
| class power_BacklightControl(test.test): |
| version = 1 |
| # Minimum number of steps expected between min and max brightness levels. |
| _min_num_steps = 4 |
| # Minimum required percentage change in energy rate between transitions |
| # (max -> min, min-> off) |
| _energy_rate_change_threshold_percent = 5 |
| |
| |
| def initialize(self): |
| """Perform necessary initialization prior to test run. |
| |
| Private Attributes: |
| _backlight: power_utils.Backlight object |
| """ |
| super(power_BacklightControl, self).initialize() |
| self._backlight = None |
| |
| |
| def run_once(self): |
| # Require that this test be run on battery with at least 5% charge |
| status = power_status.get_status() |
| status.assert_battery_state(5) |
| |
| prefs = { 'has_ambient_light_sensor' : 0, |
| 'ignore_external_policy' : 1, |
| 'plugged_dim_ms' : 7200000, |
| 'plugged_off_ms' : 9000000, |
| 'plugged_suspend_ms' : 18000000, |
| 'unplugged_dim_ms' : 7200000, |
| 'unplugged_off_ms' : 9000000, |
| 'unplugged_suspend_ms' : 18000000 } |
| self._pref_change = power_utils.PowerPrefChanger(prefs) |
| |
| keyvals = {} |
| num_errors = 0 |
| |
| # These are the expected ratios of energy rate between max, min, and off |
| # (zero) brightness levels. e.g. when changing from max to min, the |
| # energy rate must become <= (max_energy_rate * max_to_min_factor). |
| max_to_min_factor = \ |
| 1.0 - self._energy_rate_change_threshold_percent / 100.0 |
| min_to_off_factor = \ |
| 1.0 - self._energy_rate_change_threshold_percent / 100.0 |
| off_to_max_factor = 1.0 / (max_to_min_factor * min_to_off_factor) |
| |
| # Determine the number of outputs that are on. |
| starting_num_outputs_on = get_num_outputs_on() |
| if starting_num_outputs_on == 0: |
| raise error.TestFail('At least one display output must be on.') |
| keyvals['starting_num_outputs_on'] = starting_num_outputs_on |
| |
| self._backlight = power_utils.Backlight() |
| keyvals['max_brightness'] = self._backlight.get_max_level() |
| if keyvals['max_brightness'] <= self._min_num_steps: |
| raise error.TestFail('Must have at least %d backlight levels' % |
| (self._min_num_steps + 1)) |
| |
| keyvals['initial_brightness'] = self._backlight.get_level() |
| |
| self._wait_for_stable_energy_rate() |
| keyvals['initial_power_w'] = self._get_current_energy_rate() |
| |
| self._backlight_controller = power_utils.BacklightController() |
| self._backlight_controller.set_brightness_to_max() |
| |
| current_brightness = \ |
| utils.wait_for_value(self._backlight.get_level, |
| max_threshold=keyvals['max_brightness']) |
| if current_brightness != keyvals['max_brightness']: |
| num_errors += 1 |
| logging.error(('Failed to increase brightness to max, ' + \ |
| 'brightness is %d.') % current_brightness) |
| else: |
| self._wait_for_stable_energy_rate() |
| keyvals['max_brightness_power_w'] = self._get_current_energy_rate() |
| |
| # Set brightness to minimum without going to zero. |
| # Note that we don't know what the minimum brightness is, so just set |
| # min_threshold=0 to use the timeout to wait for the brightness to |
| # settle. |
| self._backlight_controller.set_brightness_to_min() |
| current_brightness = utils.wait_for_value( |
| self._backlight.get_level, |
| min_threshold=(keyvals['max_brightness'] / 2 - 1)) |
| if current_brightness >= keyvals['max_brightness'] / 2 or \ |
| current_brightness == 0: |
| num_errors += 1 |
| logging.error('Brightness is not at minimum non-zero level: %d' % |
| current_brightness) |
| else: |
| self._wait_for_stable_energy_rate() |
| keyvals['min_brightness_power_w'] = self._get_current_energy_rate() |
| |
| # Turn off the screen by decreasing brightness one more time with |
| # allow_off=True. |
| self._backlight_controller.decrease_brightness(True) |
| current_brightness = utils.wait_for_value( |
| self._backlight.get_level, min_threshold=0) |
| if current_brightness != 0: |
| num_errors += 1 |
| logging.error('Brightness is %d, expecting 0.' % current_brightness) |
| |
| # Wait for screen to turn off. |
| num_outputs_on = utils.wait_for_value( |
| get_num_outputs_on, min_threshold=(starting_num_outputs_on - 1)) |
| keyvals['outputs_on_after_screen_off'] = num_outputs_on |
| if num_outputs_on >= starting_num_outputs_on: |
| num_errors += 1 |
| logging.error('At least one display must have been turned off. ' + \ |
| 'Number of displays on: %s' % num_outputs_on) |
| else: |
| self._wait_for_stable_energy_rate() |
| keyvals['screen_off_power_w'] = self._get_current_energy_rate() |
| |
| # Set brightness to max. |
| self._backlight_controller.set_brightness_to_max() |
| current_brightness = utils.wait_for_value( |
| self._backlight.get_level, max_threshold=keyvals['max_brightness']) |
| if current_brightness != keyvals['max_brightness']: |
| num_errors += 1 |
| logging.error(('Failed to increase brightness to max, ' + \ |
| 'brightness is %d.') % current_brightness) |
| |
| # Verify that the same number of outputs are on as before. |
| num_outputs_on = get_num_outputs_on() |
| keyvals['outputs_on_at_end'] = num_outputs_on |
| if num_outputs_on != starting_num_outputs_on: |
| num_errors += 1 |
| logging.error(('Number of displays turned on should be same as ' + \ |
| 'at start. Number of displays on: %s') % |
| num_outputs_on) |
| |
| self._wait_for_stable_energy_rate() |
| keyvals['final_power_w'] = self._get_current_energy_rate() |
| |
| # Energy rate must have changed significantly between transitions. |
| if 'max_brightness_power_w' in keyvals and \ |
| 'min_brightness_power_w' in keyvals and \ |
| keyvals['min_brightness_power_w'] >= \ |
| keyvals['max_brightness_power_w'] * max_to_min_factor: |
| num_errors += 1 |
| logging.error('Power draw did not decrease enough when ' + \ |
| 'brightness was decreased from max to min.') |
| |
| if 'screen_off_power_w' in keyvals and \ |
| 'min_brightness_power_w' in keyvals and \ |
| keyvals['screen_off_power_w'] >= \ |
| keyvals['min_brightness_power_w'] * min_to_off_factor: |
| num_errors += 1 |
| logging.error('Power draw did not decrease enough when screen ' + \ |
| 'was turned off.') |
| |
| if num_outputs_on == starting_num_outputs_on and \ |
| 'screen_off_power_w' in keyvals and \ |
| keyvals['final_power_w'] <= \ |
| keyvals['screen_off_power_w'] * off_to_max_factor: |
| num_errors += 1 |
| logging.error('Power draw did not increase enough after ' + \ |
| 'turning screen on.') |
| |
| self.write_perf_keyval(keyvals) |
| |
| if num_errors > 0: |
| raise error.TestFail('Test failed with %d errors' % num_errors) |
| |
| |
| def cleanup(self): |
| if self._backlight: |
| self._backlight.restore() |
| super(power_BacklightControl, self).cleanup() |
| |
| |
| def _get_current_energy_rate(self): |
| return power_status.get_status().battery[0].energy_rate |
| |
| |
| def _wait_for_stable_energy_rate(self, |
| max_variation_percent=5, |
| sample_delay_sec=1, |
| window_size=10, |
| timeout_sec=30): |
| """ |
| Waits for the energy rate to stablize. Stability criterion: |
| The last |window_size| samples of energy rate do not deviate from |
| their mean by more than |max_variation_percent|. |
| |
| Arguments: |
| max_variation_percent Percentage of allowed deviation from mean |
| energy rate to still be considered stable. |
| sample_delay_sec Time to wait between each reading of the |
| energy rate. |
| window_size Number of energy rate samples required to |
| measure stability. If there are more |
| samples than this amount, use only the last |
| |window_size| values. |
| timeout_sec If stability has not been attained after |
| this long, stop waiting. |
| |
| Return value: |
| True if energy rate stabilized before timeout. |
| False if timed out waiting for energy rate to stabilize. |
| """ |
| start_time = time.time() |
| samples = [] |
| max_variation_factor = max_variation_percent / 100.0 |
| while time.time() - start_time < timeout_sec: |
| current_rate = self._get_current_energy_rate() |
| |
| # Remove the oldest value if the list of energy rate samples is at |
| # the maximum limit |window_size|, before appending a new value. |
| if len(samples) >= window_size: |
| samples = samples[1:] |
| samples.append(current_rate) |
| |
| mean = sum(samples) / len(samples) |
| if len(samples) >= window_size and \ |
| max(samples) <= mean * (1 + max_variation_factor) and \ |
| min(samples) >= mean * (1 - max_variation_factor): |
| return True |
| |
| time.sleep(sample_delay_sec) |
| |
| return False |
