Raspberry Pi4 model B 3.5 mm audio / HDMI issue

[Victor]

Hello Everyone,

After the "OMAP3 not supported" notice, I switched to Raspberry Pi4 B.
There is another issue with it. There is no audio output signal nor on the second HDMI port neither on 3.5 mm jack.
I read RiscOS Wiki article about it and it declares that this is a problem of RISCOS driver.
However the JASPP games and ADFFS start fine when display is plugged into HDMI2. Unfortunately there is no sound of any kind on any port.
Which is sad.

When I switch to the HDMI1 (closest to USB-C connector.) The system generates sound normally
but starting games with ADFFS brings it to the black screen. (The game starts - I can hear the sounds from it)

In simple words - I can see the game running but can't hear it running or vice versa.
It only depends on what port the display is connected to.


My CMDLINE/TXT contains:

disable gamma
disable_mode_changes

and CONFIG/TXT:

fake_vsync_isr=1
disable_overscan=1
hdmi_ignore_edid_audio=1
audio_pwm_mode=2


What is the difference for ADFFS if the system uses HDMI1 or HDMI2 port?
(monitor is the same, MDF is the same, no changes in config files)

Completely OT:
On RaspberryPi OS 3.5 mm audio output always works fine with any HDMI port.
Maybe I am wrong saying that but to me it sounds like there must be a configuration flag of some kind to enable 3.5mm output
no matter what HDMI port is in use.

[Victor]

Oh.. I just read the RISCOS and Pi firmware information page carefully.
https://www.riscosopen.org/wiki/documen ... 20Firmware
and at the very bottom I found that CMDLINE parameters have to be space separated.
Not like in the CONFIG file I changed the layout and voila it all works!
However strange behavior that I described in original topic might help you
to trace some bugs. There should not be any difference to what HDMI port the monitor is plugged in.
To say true it might be RISCOS itself not the ADFFS.

[JonAbbott]

There is no audio output signal nor on the second HDMI port neither on 3.5 mm jack.
I read RiscOS Wiki article about it and it declares that this is a problem of RISCOS driver.

Yes, I believe that's a known issue as RISC OS does not have an audio driver for the secondary HDMI port.

When I switch to the HDMI1 (closest to USB-C connector.) The system generates sound normally
but starting games with ADFFS brings it to the black screen.

That sounds like EDID is enabled, which essentially disables the Pi upscaler. disable_mode_changes in CMDLINE/TXT should fix that.

What is the difference for ADFFS if the system uses HDMI1 or HDMI2 port?
(monitor is the same, MDF is the same, no changes in config files)

ADFFS isn't monitor aware, it just translates the video output to the current video device that was being used for the desktop. Essentially what happens when you change to a legacy mode is a translation GraphicsV driver takes over, that translates everything through to the original GraphicsV driver but with 24bit forced. Drop to BASIC and see which output MODE 13 appears on to confirm its on the primary monitor.

I've tried to purchase a Pi4 many times over the past 3 years, so I could check support as I know it has differences to earlier models, but every order has been annoyingly cancelled due to supply issues. The last order I placed in Feb of this year had a ship date of mid 2024!

On RaspberryPi OS 3.5 mm audio output always works fine with any HDMI port.
Maybe I am wrong saying that but to me it sounds like there must be a configuration flag of some kind to enable 3.5mm output
no matter what HDMI port is in use.

Refer to the Pi CONFIG/TXT settings. Audio via the jack is disable_audio_dither=1 and via HDMI is hdmi_force_edid_audio=1 - I'm going to guess that's forced to HDMI1 on a Pi4, but don't really know if I'm honest.

and at the very bottom I found that CMDLINE parameters have to be space separated.

I cover making changes to that file in the Pi requirement section on the ADFFS download page along with other pre-reqs.