No audio on Samsung Galaxy A21s when MMAP is enabled

[kus04e4ek]

Android version(s): 12
Android device(s): Samsung Galaxy A21s
Oboe version: 1.8.1
App name used for testing: OboeTester

Short description
Completely silent when using built-in speakers with MMAP enabled. Bluetooth headphones work fine.

Steps to reproduce
Test Output with default options.

Device
ro.product.brand = samsung
ro.product.manufacturer = samsung
ro.product.model = SM-A217F
ro.product.device = a21s
ro.product.cpu.abi = arm64-v8a
ro.build.description = a21snsxx-user 12 SP1A.210812.016 A217FXXSADWI1 release-keys
ro.hardware = exynos850
ro.hardware.chipname = exynos850
ro.arch = exynos850
| grep aaudio = [aaudio.hw_burst_min_usec]: [2000]
[aaudio.mmap_exclusive_policy]: [2]
[aaudio.mmap_policy]: [2]

[kus04e4ek]

Ran Data Paths.
data paths.zip

[robertwu1]

It's really strange because your device is only opening shared streams. Can you attach a bug report?

[philburk]

It's really strange because your device is only opening shared streams.

It seems OboeTester is only requesting Shared streams and not Exclusive streams.
It was probably considered redundant because Shared streams are built on top of Exclusive streams.
So if Exclusive failed then Shared would fail.

[philburk]

I created an internal bug for Samsung:
b/322234897 | P2 | Samsung A21S audio MMAP output is silent

[kus04e4ek]

It looks like I can't reproduce it anymore. Ran Data Paths again and every test passed. I restarted my phone not too long ago, so maybe MMAP output just broke after some time of my phone being active?
data_paths.zip

[kus04e4ek]

Also, I noticed that audio stream still gets exclusive sharing mode even if there is audio playing in the other app. I might understand exclusive sharing mode wrong, but isn't it supposed to work only if one audio stream is playing, so that it would be possible to directly write audio data to the output? If I understand the mode correctly, then it might be possible that the device just tells the app that exclusive sharing mode is obtained when it actually failed and the same happens with MMAP.

[kus04e4ek]

Also, I noticed that audio stream still gets exclusive sharing mode even if there is audio playing in the other app.

Audio stream didn't get exclusive sharing mode when I ran the app that requests exclusive sharing mode. But audio stream gets exclusive sharing mode when the other app requests shared sharing mode. Is this expected behavior?

[philburk]

The EXCLUSIVE mode is for exclusive access to the special MMAP path.
It is not exclusive for all audio. Other apps can play audio over the Legacy (non-MMAP) path even when your app have EXCLUSIVE MMAP access.

[philburk]

I pinged Samsung.

[philburk]

Samsung was unable to reproduce this problem.

@kus04e4ek says they rebooted their phone and now MMAP output is working.
So I think the framework or HAL got into some broken state and was unable to recover without rebooting.
This is probably not specific to the A21S.

I will close this because we cannot reproduce the issue and do not have enough information to move forward.