AMDGPU & Nouveau Getting HDMI CEC Support For DisplayPort/USB-C To HDMI Adapters

Another drm-misc-next pull request was sent in Wednesday with new feature material slated for the Linux 4.20~5.0 kernel release by way of DRM-Next.

This batch of miscellaneous changes does include an AMDGPU and Nouveau addition this time around. After the Linux 4.19 kernel added the infrastructure work for supporting HDMI CEC with DisplayPort / USB Type-C to HDMI adapters, that support is now wired through to the AMDGPU and Nouveau DRM drivers. HDMI CEC, of course, is the Consumer Electronics Control specification that allows for one remote/controller to send command and control signals over the HDMI link to connected devices. HDMI CEC is pretty nifty and its mainline kernel support in general has been brought up over the past number of kernel cycles. With Linux 4.20~5.0, AMDGPU and Radeon can now handle passing CEC commands when using these DP/USB-C to HDMI adapters thanks to these new "CEC-Tunneling-over-AUX" patches.

More details on the current Linux CEC state including supported adapters can be found via this text document.

There is also new common code for user-space to be able to easily convert MEMFD regions into DMA-BUFs. Also notable with this drm-misc-next work is support for the Allwinner A64 display support within the Sun4i DRM driver. The A64 SoC with its four Cortex-A53 cores and Mali-400 MP2 GPU is found most commonly in the PINE64 ARM SBC as well as various other boards like the NanoPi A64.

Details on this latest batch of changes can be found via this pull request.