No HDMI audio output from AMD Laptop

Question

My Laptop is a Dell Inspiron M5110, that runs Ubuntu 12.10. When I plug in HDMI to my 39 inch 1080p Television and play a audio file, sound comes out through the laptop speakers. The HDMI video seems to work normally.

My graphics card is a AMD Radeon HD 6620G, integrated on my AMD A8-M3500 APU CPU. I am using the Open-Source graphics drivers. I ran the aplay -l command and the results are this:

    dell1@Dell-Inspiron-M5110-Laptop-Ubuntu:~$ aplay -l

    **** List of PLAYBACK Hardware Devices ****
    card 0: Generic [HD-Audio Generic], device 3: HDMI 0 [HDMI 0]
      Subdevices: 1/1
      Subdevice #0: subdevice #0
    card 1: Generic_1 [HD-Audio Generic], device 0: STAC92xx Analog [STAC92xx Analog]
      Subdevices: 1/1
      Subdevice #0: subdevice #0
    dell1@Dell-Inspiron-M5110-Laptop-Ubuntu:~$

From what was listed above, Ubuntu does not detect a HDMI Audio output, nor is it listed in the Sound Settings.

I also altered the /etc/default/grub file from this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.audio=1"

Once I did that, a HDMI/DisplayPort 1 audio device showed up in Sound Settings, but it didn't work. So I reverted my changes in that file to its default, since it didn't work.

Any help is appreciated.

Answer 1

I altered the Grub file again and found out that it works, though the first time I did it, it didn't work.

This time the HDMI/DisplayPort showed up, but with no number after it. There is a little 1 second delay before the Audio goes to the TV but it is nothing major.