It seems the start up sound occupies the audio device (http://crrev.com/c/1160143). It cause test fail. We should disable CRAS when we run ALSA test.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/b31821936f173396d135b07a72a4328d95b817bd

commit b31821936f173396d135b07a72a4328d95b817bd
Author: Yu-Hsuan Hsu <yuhsuan@google.com>
Date: Thu Aug 30 04:05:51 2018

[autotest] Stop CRAS before running ALSA test

If we run ALSA test while another stream is playing in CRAS, the test won't
get audio device so that it will return error. We should stop CRAS before
running to make sure this situation will not happen.

BUG= chromium:878410 
TEST=audio_AlsaLoopback, audio_Aplay, audio_AlsaAPI test can pass reliably on
peppy.

Change-Id: I8d83487e8fb252aaa156c954255f5b1daed9c6bb
Reviewed-on: https://chromium-review.googlesource.com/1195229
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>

[modify] https://crrev.com/b31821936f173396d135b07a72a4328d95b817bd/client/site_tests/audio_AlsaLoopback/audio_AlsaLoopback.py
[modify] https://crrev.com/b31821936f173396d135b07a72a4328d95b817bd/client/site_tests/audio_Aplay/audio_Aplay.py
[modify] https://crrev.com/b31821936f173396d135b07a72a4328d95b817bd/client/site_tests/audio_AlsaAPI/audio_AlsaAPI.py

The change fixed the bug in the test which fails on M69. So request merge to M69. Because it's just a test, it won't break anything. Thanks.

This bug requires manual review: We are only 3 days from stable.
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), kariahda@(iOS), cindyb@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/38f7559ed7cd83169f60b1028f8b91b805e2806b

commit 38f7559ed7cd83169f60b1028f8b91b805e2806b
Author: Yu-Hsuan Hsu <yuhsuan@google.com>
Date: Wed Sep 05 12:11:53 2018

[autotest] Stop UI before running CRAS rms test

If we run CRAS test while another stream is playing in CRAS, the test
can not get stream count 0 so that it will return timeout. We should
stop UI before running test to make sure this situation will not happen.

BUG= chromium:878410 
TEST=audio_CrasLoopback, audio_CRASFormatConversion test can pass reliably on
peppy.

Change-Id: Id9d34d1bcf62b29081eec0c589070f72e790e7ee
Reviewed-on: https://chromium-review.googlesource.com/1198910
Commit-Ready: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Tested-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>

[modify] https://crrev.com/38f7559ed7cd83169f60b1028f8b91b805e2806b/client/cros/audio/audio_helper.py

I want to land these two changes on M69. They are all for test should not break anything. Thanks!

This bug requires manual review: Request affecting a post-stable build
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), kariahda@(iOS), cindyb@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Because this one landed in M71, it should merge into M70 first. So request merge to M70.
https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1198910

The cheery-pick link: crrev.com/c/1215562
It is about test updated so it won't break anything. Thanks.

Approved for M70

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/aa15fdc223c10f386c311b7ee2fab7f6589aa488

commit aa15fdc223c10f386c311b7ee2fab7f6589aa488
Author: Yu-Hsuan Hsu <yuhsuan@google.com>
Date: Tue Sep 11 02:23:03 2018

[autotest] Stop UI before running CRAS rms test

If we run CRAS test while another stream is playing in CRAS, the test
can not get stream count 0 so that it will return timeout. We should
stop UI before running test to make sure this situation will not happen.

BUG= chromium:878410 
TEST=audio_CrasLoopback, audio_CRASFormatConversion test can pass reliably on
peppy.

Change-Id: Id9d34d1bcf62b29081eec0c589070f72e790e7ee
Previous-Reviewed-on: https://chromium-review.googlesource.com/1198910
(cherry picked from commit 223cc505e13accb0bbed4ee0abd706709b3b1db7)
Reviewed-on: https://chromium-review.googlesource.com/1215562
Reviewed-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Commit-Queue: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Tested-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>

[modify] https://crrev.com/aa15fdc223c10f386c311b7ee2fab7f6589aa488/client/cros/audio/audio_helper.py

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Hello, I still need to land these two changes on M69 because our test on M69 are still broken. Thanks.

The milestone owner @cindyb didn't allow to merge these fixes into stable branch R69 because it's not a P0 bug. The test will keep failing on R69. We need to wait until next branch cut.