Debian Hardware :: 5.1 With HDMI And ATI

So, i've installed a Debian Jessie (minimal install "gnome-core") and i'm using an ATI radeon R5 230, with libre driver (and non-free firmware) and all works well in stereo.

But i'm looking for surround sound via HDMI (5.1).

My configuration is : PC --- HDMI ---> Pioneer Receiver ---- HDMI ----> Screen

The receiver looks well detected as seen in the eld file :

Code: Select allcat /proc/asound/card1/eld#0.0
Code: Select allmonitor_present      1
eld_valid      1
monitor_name      
connection_type      HDMI
eld_version      [0x2] CEA-861D or below
edid_version      [0x0] no CEA EDID Timing Extension block present

[Code] ....

I've created a udev rule for pulseaudio for loading a personal conf file with a profile i've created.

Code: Select allATTRS{vendor}=="0x1002", ATTRS{device}=="0xaa98", ENV{PULSE_PROFILE_SET}="HDMI5.1.conf"

Code: Select all[Mapping hdmi-surround-51]
device-strings = hdmi:%f
channel-map = front-left,front-right,rear-left,rear-right,front-center,lfe
description = Surround 5.1 (HDMI)
priority = 2
direction = output
paths-output = hdmi-output-0

It works great (I can see 6 channels in pavucontrol or via "sound" in "settings"), but i got "duplicate stereo" and not real 5.1

If I made a speaker test, all tests makes sounds comes from the Front center speaker (and front R and L with less volume)... but not real 5.1 ....

Can we (and how ?) get 5.1 via HMDI with an ATI and free drivers ?