Pure Data won't make any sound until UI is displayed via a X-Window on a PC

[MrDham]

Describe the bug
Pure Date presets don't make any sound if Zynthian is not connected to a PC and if UI is not displayed on this PC (by using "ssh -Y root@zynthian.local")

To Reproduce
Steps to reproduce the behavior:
Case 1:
Connect Zynthian to an audio amplifier
Create a new layer with PD > generative/generative_relaxing

Result: No sound can be heard

Case 2
Connect Zynthian to audio amplifier
Connect a PC via ethernet and log to a X-Window using "ssh -Y root@zynthian.local"
Create a new layer with PD > generative/generative_relaxing
Result : The UI is dispayed on the PC and some automatically generated sound can be heard

Expected behavior
We should hear an automatically generated sound in both case 1 and 2.
But we have some sound in case 2 only.

Screenshots
N/A

Setup:

• SD-image
  Aruk RC3
• Hardware Config
  Raspberry Pi 3 Model B Plus Rev 1.3
  Soundcard: HifiBerry DAC+
  Display: PiScreen 3.5 (v2)
  Wiring: MCP23017_EXTRA
• Software Version
  zyncoder: master (80862b6)
  zynthian-ui: master (3688c73)
  zynthian-sys: master (26f86d2)
  zynthian-data: master (676c32a)
  zynthian-webconf: master (0094c99)

Additional context
PC conf for X-Window: Xming + Putty on a windows PC (for case 2)

[jofemodo]

Sorry. I can't reproduce the problem. For me it's working like a charm ...
Could somebody else check it?

[MrDham]

Hi.
I made some further investigations.
I tested it with Aruk RC2 (without any update) and it works well.
I tested it with Aruk RC3 without any update (freshly burnt SD card with Aruk RC3) and the problem is there.

The problem seem to appear somewhere between RC2 and RC3.

[jofemodo]

You are right. I'm trying to fix it but i've no idea where the problem is ... or better, i can't find any difference between RC-2 and RC-3 regarding puredata ;-)

[MrDham]

I just made some further investigation.
In RC2, I can get same symptom with the following scenario:
Start Zynthian with no layer.
Open a X window using "ssh -Y root@zynthian.local"
Enter password and then close the session.
Then create a new layer with PD > generative/generative_relaxing.

   No sound can be heard.  

Reboot

  Some relaxing sound can be heard

Maybe search the bug on X window side (a "phantom" x window session in RC3, ... ?)

I hope it will help :-)

[MrDham]

Mistakenly closed when posting my previous comment.

[jofemodo]

It should be solved now. Update and test, please.

[MrDham]

I updated and tested. It works well now. Thanks.