Using HDMI With ATI Radeon HD Linux Drivers

Unfortunately, the HDMI audio at this time wasn't nice. Ubuntu 7.10 ships with ALSA 1.0.14, so we had manually compiled ALSA 1.0.15. A patch for R600, RS600, RS690, RS780 HDMI audio support was originally released by AMD earlier this year, and is present in this latest version of ALSA (Advanced Linux Sound Architecture). However, ALSA was unable to properly detect and utilize this ATI R600 HDMI audio adapter through the hda-intel driver. For the record, there are bugs present in ALSA 1.0.15 that affect other adapters using HDMI audio as well. For right now, using the HDMI audio with the latest ATI Radeon HD graphics cards isn't a trouble-free experience, but hopefully once ALSA 1.0.16 is out the door these problems will be eliminated.

After the success using the proprietary ATI driver, we had turned to the latest git code for xf86-video-radeonhd. Using this open-source driver, the detected EDID information from the Sharp LC37D43U LCD HDTV had the system running at 1280 x 720. We had then manually added a 1920 x 1080 mode in the xorg.conf, but still the RadeonHD driver had turned back to this lower resolution. Aside from the resolution disparity, the RadeonHD driver worked fine as would be expected for this HDMI adapter.

If you have any additional questions or would like to share your Linux HDMI results, be sure to let us know in the Phoronix Forums.