BeagleBoneBlack HDMI audio on Android RowBoat do not work, Angstron works

Rafael Coutinho

Hi,

for some reason using Android RowBoat with 1280x720 makes HDMI to work with my monitor (LG one) however there is no audio (even being the right cea mode).

Although on Angstron that comes in BBB from factory it does.

The main difference I believe is kernel version (3.2 on Rowboat and 3.8 on Angstron)

Is there a way to backport only the HDMI drivers from angstron to rowboat kernel?

Which driver are related to it? only tda998x?

Besides for some reason image does not work if I boot with HDMI cable connected to BBB. But it works if I plug it in after some seconds.

Here is the boot dmesgs,

first is with the HDMI cable disconnected

Second with the cable connected during boot (does not work but dmesg is diff)

over 8 years ago

0 Adeneo Embedded support team over 8 years ago

Mastermind 9310 points

Hello,

We tested the HDMI with a Beaglebone Black, with the official TI release of Android 4.2.2, kernel 3.2.
The video works even if the HDMI cable is connected on boot, and the audio works too.
We are using the BBB from element14 with a PCB RevB6, can you tell us what is your version and manufacturer?

0 Rafael Coutinho over 8 years ago in reply to Adeneo Embedded support team

Intellectual 330 points

Hi we are using Rev A5C. I'm planning to do the same test with Rev C today or at most monday.

However with A5C we get it working on other displays using HDMI and get audio correctly. But our customer wants to use it on a specific monitor that as describe works fine when using Angstron on BBB, however it does not using Rowboat. Even not being the latest Rev.

Our question is which drivers are involved on this so we could at least try to migrate those to Rowboat kernel.

Anyway will report back with the test using Rev C

0 Adeneo Embedded support team over 8 years ago in reply to Rafael Coutinho

Mastermind 9310 points

Hello,

We checked the schematics of the Beaglebone Black. The TDA19988 is an HDMI transmitter which will mix RGB signals and audio to HDMI signals.
This is the only chip connected between the AM335x SOC and the HDMI connector, so if there is no audio the tda998x driver seems to be the only culprit.

0 Rafael Coutinho over 8 years ago in reply to Adeneo Embedded support team

Intellectual 330 points

Tested using RevC and still have the same problem. Here is the DMESG

http://pastebin.com/Q1XWqiSw

I wonder why it works on Angstron distribuition and not Rowboat... the kernel is different but the driver is the same.

Any suggestions on how to debug it?

0 Rafael Coutinho over 8 years ago in reply to Rafael Coutinho

Intellectual 330 points

By the way, I just downloaded this pre built image:
downloads.ti.com/.../TI_Android_JB_4.2.2_DevKit_4.1.1_beagleboneblack.tar.gz

And cannot get audio to work.

0 Rafael Coutinho over 8 years ago in reply to Rafael Coutinho

Intellectual 330 points

Same beagle with Angstrom we get audio with the same resolution... but prebuilt TI Android... no audio. (I'm using Android on a SDCard).

Besides, when using Android, we cannot boot the board with HDMI plugged in, otherwise no image on the HDMI.

On other displays it works, however this display that we need to validate has this strange behavior. Need help identify what's diff between to two.

0 Adeneo Embedded support team over 8 years ago in reply to Rafael Coutinho

Mastermind 9310 points

Hello,

Unfortunately since the issue occurs only with your display we will not be able to help you much on that.
You can try to launch the kernel with a higher log level - loglevel option, see here: git.kernel.org/.../kernel-parameters.txt
You can also recompile the kernel with debug messages and/or add some yourself (using "pr_debug()" and #define DEBUG)
A few more hints:
- compare the HDMI core drivers between 3.2 and 3.8 kernels
- compare the I2C commands between a display that works and the one that doesn't, if you have a logic analyzer.

We confirm that both audio and boot work when the HDMI is plugged, before or after the boot.

0 Rafael Coutinho over 8 years ago in reply to Adeneo Embedded support team

Intellectual 330 points

Some more info:

Logcat starting BBB with HDMI cable DISCONNECTED. Cable was connected at the end (logcat time ~00:00:30).
http://pastebin.com/qb3sUWsa

Logcat starting BBB with HDMI cable CONNECTED during boot.
http://pastebin.com/13qabECk

Result of adb shell dumpsys media.audio_flinger during audio output (with connected cable)
http://pastebin.com/CXYjgqYQ

Out put of get-edid
http://pastebin.com/HZ08njNs

0 Adeneo Embedded support team over 8 years ago in reply to Rafael Coutinho

Mastermind 9310 points

Hello,

We will give a more detailed look in the future, but with a quick overlook we didn't see something wrong.
You should note that since the problem seems to be tied with a particular screen on your side, we won't be able to spend much time on it.

0 Adeneo Embedded support team over 8 years ago in reply to Rafael Coutinho

Mastermind 9310 points

Hello,

Reading from the logcat didn't gave anything useful.
Can you post a dmesg of your tests, or what the UART shows?
It can be also useful to have a dumpsys of SurfaceFlinger - it manages the graphic, maybe it will shows something about a screen connected.

Other than that, we will try to see if there is a difference about the HDMI or audio core between Linux 3.2 and 3.8.
When you checked the difference between the 3.2 and 3.8, did you saw something on the HDMI or audio?

0 Rafael Coutinho over 8 years ago in reply to Adeneo Embedded support team

Intellectual 330 points

I have compared the driver tda998x that you mentioned that might be the only one related and there is not any changes.

Not sure about others

0 Adeneo Embedded support team over 8 years ago in reply to Rafael Coutinho

Mastermind 9310 points

Hi Rafael,

Can you post a dmesg of your tests, or what the UART shows?
It can be also useful to have a dumpsys of SurfaceFlinger - it manages the graphic, maybe it will shows something about a screen connected.

Also, maybe there is a difference about the HDMI or audio core between Linux 3.2 and 3.8.

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BeagleBoneBlack HDMI audio on Android RowBoat do not work, Angstron works