[PROBLEM] Added screen now no sound over hdmi

[adolfotregosa]

I added the official pi 7" screen today and now have no sound.
If I disconnect power to the screen sound returns.
If I just turn off the local UI display setting I have no sound.
I am using hdmi to an avr
Is it not possible to output audio over hdmi with a screen attached?
Pi 3b+

Hi. I came across this very issue with my raspberry pi 4 and the official 7 inch DSI display and the fix for it (after going to hell and back) was to edit the boot/config.txt file and add the following:

max_framebuffers=2
framebuffer_priority=0
hdmi_channel_map=335201480


for users with rpi4, only hdmi-0 will work. 

hdmi_channel_map=335201480 maps the channels to the (at least for me) typical FL,FR,C,LFE... and not FL,FR,SL,SR....

I'm using camilladps for bass management and convolution. Works beautifully.

Hopefully this helps you.

Interesting.

Do you have links that explain what these settings do?

Code:

max_framebuffers=2
framebuffer_priority=0
hdmi_channel_map=335201480

hdmi_channel_map I explained above. The rest right from the lion mouth;

https://www.raspberrypi.com/documentatio...g_txt.html


framebuffer_priority
In a system with multiple displays, using the legacy (pre-KMS) graphics driver, this forces a specific internal display device to be the first Linux framebuffer (i.e. /dev/fb0).

The options that can be set are:

Display ID
Main LCD

0

Secondary LCD

1

HDMI 0

2

Composite

3

HDMI 1

7

max_framebuffers
This configuration entry sets the maximum number of firmware framebuffers that can be created. Valid options are 0, 1, and 2. By default on devices before the Raspberry Pi 4 this is set to 1, so will need to be increased to 2 when using more than one display, for example HDMI and a DSI or DPI display. The Raspberry Pi 4 configuration sets this to 2 by default as it has two HDMI ports.

Generally in most cases it is safe to set this to 2, as framebuffers will only be created when an attached device is actually detected.

Setting this value to 0 can be used to reduce memory requirements when used in headless mode as it will prevent any framebuffers from being allocated.