A few months back HDMI audio support
came to the ATI Radeon kernel mode-setting driver and while this support is in place with the mainline kernel, it's only supported up through the ATI R600 hardware with the KMS driver. However, HDMI audio support for the R700 (Radeon HD 4000 series) is soon coming. Rafał Miłecki who has done much of the HDMI audio work for the open-source ATI driver stack has shared that he has achieved R700 audio success and the support may land in as soon as the Linux 2.6.34 kernel
The latest patches clean up the HDMI audio support and makes it compatible with a greater range of ATI hardware, and new bits for DCE 3.2 GPUs. The new patch(es) should be published in the coming days and will hopefully be merged in time for the 2.6.34 kernel release. The announcement was made on Rafał's blog
. AMD has had patches for greater HDMI audio support (including audio interrupts), but these patches have been held up in legal review for months and so Rafał came up with this new alternative.