[alsa-devel] ALSA: hda: hdmi: Hint matching between input devices and pcm devices

Pierre-Louis Bossart pierre-louis.bossart at linux.intel.com
Tue Aug 30 00:14:23 CEST 2011

> Since modern HDMI cards often have more than one output pin and thus
> input device, we need to know which one has actually been plugged in.
> This patch adds a name hint that indicates which PCM device is connected
> to which pin.

I've been thinking about this, and there's some additional work needed
for the jack-detection to be useful.
User-space code will need at some point to rely on the ELD information
to know what the HDMI receiver supports, eg to enable/disable
passthrough. I hacked a while ago a small patch to make the ELD bytes
available in a control (see attached). It seems to work but I wasn't too
sure how to expose it. 
Should we define a convention for the name of this control as well? Or
is there a way to link a control to a specify PCM device?
Thanks for your feedback,
-------------- next part --------------
A non-text attachment was scrubbed...
Name: eld.patch
Type: text/x-patch
Size: 4819 bytes
Desc: not available
Url : http://mailman.alsa-project.org/pipermail/alsa-devel/attachments/20110829/e36106de/attachment-0001.patch 

More information about the Alsa-devel mailing list