Comment 13 for bug 974963

Same issue. Using fglrx radeon 5650. Worked fine in 11.10. I have a different "workaround":
I plug in HDMI, only after that i can choose the input on my tv. There is no HDMI output in sound settings. If i plug out HDMI and plug it in again, it will be in the settings.

Doing a short watch "dmesg | tail -20" got me:

Plug in - TV is not set to HDMI-Input (no entry in settings):
[ 2678.137879] HDMI hot plug event: Codec=0 Pin=3 Presence_Detect=1 ELD_Valid=1
[ 2678.137899] HDMI status: Codec=0 Pin=3 Presence_Detect=1 ELD_Valid=1
[ 2678.137950] HDMI hot plug event: Codec=0 Pin=3 Presence_Detect=0 ELD_Valid=0
[ 2678.137965] HDMI status: Codec=0 Pin=3 Presence_Detect=0 ELD_Valid=0

Selecting HDMI on TV (nothing happens) - plug out, plug in (entry in settings):
[ 2678.161597] HDMI hot plug event: Codec=0 Pin=3 Presence_Detect=0 ELD_Valid=1
[ 2678.161621] HDMI status: Codec=0 Pin=3 Presence_Detect=1 ELD_Valid=1

Unselecting HDMI on TV (entry in sound settings gone)
[ 2707.224468] HDMI hot plug event: Codec=0 Pin=3 Presence_Detect=0 ELD_Valid=0
[ 2707.224494] HDMI status: Codec=0 Pin=3 Presence_Detect=0 ELD_Valid=0

Selecting HDMI again does nothing.

Im no expert in this things, but to me it seems that pluggin in the first time first is detected, but immediatly set to ELD_Valid=0 after that. Pluggin out and in with selection on TV leaves the state valid and switching input on TV unsets Valid. In my case at least best option would be to show HDMI in sound settings and never "unload" it, if detected one time? Right click->disable input as option to disable it again?

It worked perfect in 11.10.