HDMI Audio for Evergreen

[DarkFoss]

hehe sounds like you'll need to send a Popeil pocket dev with that card droidhacker

[darkbasic]

Sending some hardware is not a problem, but I definitely prefer video decoding

[droidhacker]

Sending some hardware is not a problem, but I definitely prefer video decoding

Yeah, I tend to agree with that. Video decoding is a much more significant undertaking. Conflicted now.... sending a card may be a distraction.

Understanding how the hardware work isn't as hard as it sounds in the first place.

Really? I myself wouldn't mind hacking on it... only problem is I have no idea where to begin. My background is in network protocols, my only experience in video card drivers involves being hand held by Alex through hacking on the radeon KMS driver to get the defective (by design) DP port on my mainboard activated in DVI mode.... ECS had the brilliant idea to not hook up all the pins.

[Deathsimple]

Really? I myself wouldn't mind hacking on it... only problem is I have no idea where to begin. My background is in network protocols, my only experience in video card drivers involves being hand held by Alex through hacking on the radeon KMS driver to get the defective (by design) DP port on my mainboard activated in DVI mode.... ECS had the brilliant idea to not hook up all the pins.

Yea, if you already touched the KMS code take a look at the following files:
drivers/gpu/drm/radeon/r600_audio.c
drivers/gpu/drm/radeon/r600_hdmi.c

The whole HDMI support is implemented mostly in these two files. r600_audio.c (just 281 lines of code) is responsible for the communication with the alsa driver and contains mostly functions to figure out the currently playing audio format. r600_hdmi.c (just 585 lines of code) uses the infos about the currently playing audio format and the current video resolution to program how the audio and video signal are mixed together into the registers of one of the HDMI blocks (there is usually one HDMI block for each display connector on your card).

Of course you need a testing environment: evergreen hardware + something that can play audio over HDMI, a pretty normal LCD television should be enough. As software you need a system were you can easily switch between a catalyst and KMS, beside that you also need radeontool (should be part of the distribution) to manually set registers in the hardware from a commandline, also all that stuff needed to compile a kernel by yourself could be helpful.

The rest should be only allot of try&error to figure out the differences between R7xx and evergreen. I would suggest starting with playing an audio file with catalyst and while playing disable the audio block with radeontool (look at the enable/disbale functions in r600_audio.c how to do this). If the audio stops playing we have made sure that the audio block is still at the same register address.

Contact me by mail and I can easily explain how to figure out the rest.

[droidhacker]

That actually looks doable.... I'm going to try this.
Going to pick up an ASUS EAH5450, nice entry level evergreen card. Cheap.

[DanL]

That actually looks doable.... I'm going to try this.
Going to pick up an ASUS EAH5450, nice entry level evergreen card. Cheap.

Hey dh, any progress/news?

[droidhacker]

Hey dh, any progress/news?

Sorry, haven't even been able to make it to the store yet.

[schwarzygesetzlos]

HDMI-audio working fine on HD 5770, but...

Finally I can enjoy HDMI-audio on my HD 5770, since kernel 3.3.x series - one cable less, hooray!

BUT
one issue is left which is annoying me:

When the screensaver kicks in, HDMI audio playback is also muted. This doesn't happen when I output the sound via SP/DIF. HDMI and SP/DIF are both connected to my DENON AVR 1612. Is there any other solution apart from disabling the screensaver completely?

[agd5f]

Finally I can enjoy HDMI-audio on my HD 5770, since kernel 3.3.x series - one cable less, hooray!

BUT
one issue is left which is annoying me:

When the screensaver kicks in, HDMI audio playback is also muted. This doesn't happen when I output the sound via SP/DIF. HDMI and SP/DIF are both connected to my DENON AVR 1612. Is there any other solution apart from disabling the screensaver completely?

The audio is mixed into the display stream, if you turn off the display, you also turn off the audio.

[schwarzygesetzlos]

The audio is mixed into the display stream, if you turn off the display, you also turn off the audio.

Thanks for the quick reply! Too bad for me then, I can't imagine an easy solution for this problem...