APPLIED[L]: [PATCH 0/1][SRU][L/U] Fail to output sound to external monitor which connects via docking station

[Andrea Righi]

On Wed, Mar 08, 2023 at 01:19:00AM +0800, Chris Chiu wrote:
> BugLink: https://bugs.launchpad.net/bugs/2009024
> 
> [Impact]
> No sound output from the external monitor which connect via some docking station. It only happens when user boot the system with docking station connected. Re-plug the docking station can fix this issue. Or plug the docking station later won't trigger this problem.
> 
> [Fix]
> Turn on the CONFIG_SND_HDA_INTEL_HDMI_SILENT in kernel config. It will start sending an "audio keepalive" to the monitor as soon as it is connected.
> 
> [Test]
> Connect the external monitor to the Atomic Type-C Dock (HD22Q) and boot the system with the dock connected. Play sound via HDMI/DP port and check if there's any audio output from the external monitor.
> 
> [Where problems could occur]
> It sends the "audio keepalive"(silent stream) to the monitor when connected. Doesn't affect original workflow of the audio system.

Applied to lunar/linux, thanks!

-Andrea