[alsa-devel] ALSA HDMI output not detected
Hi guys,
I opened a bug about HDMI sound output not detected on an NVIDIA optimus laptop. I don't know if HDMI sound card detection is up to ALSA, the kernel or the video driver. Could anyone give me a clue so the bug can be routed to its correct destination? Link to the bug: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1377653
Regards, Sam
At Wed, 22 Oct 2014 19:46:58 +0200, samuelchemla@orange.fr wrote:
Hi guys,
I opened a bug about HDMI sound output not detected on an NVIDIA optimus laptop. I don't know if HDMI sound card detection is up to ALSA, the kernel or the video driver.
Actually all of three are involved fairly tightly.
Could anyone give me a clue so the bug can be routed to its correct destination? Link to the bug: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1377653
You should start checking EDID on the video side and ELD on the audio side. ALSA driver shows the connection and ELD status in proc files and control elements. If EDID is given, but ELD (or monitor connection state) isn't, usually it's a video driver problem, e.g. the audio register bit isn't set properly.
Takashi
Hi,
there is no ELD file in /proc/asound nor /proc/asound/card0 On the EDID side, do you mean any EDID from any HDMI screen ? I thought EDID file was screen dependant. I know the screen is HDMI sound capable because I am using it with a raspberry without problem... :-)
Regards, Sam
On 23/10/2014 18:14, Takashi Iwai wrote:
At Wed, 22 Oct 2014 19:46:58 +0200, samuelchemla@orange.fr wrote:
Hi guys,
I opened a bug about HDMI sound output not detected on an NVIDIA optimus laptop. I don't know if HDMI sound card detection is up to ALSA, the kernel or the video driver.
Actually all of three are involved fairly tightly.
Could anyone give me a clue so the bug can be routed to its correct destination? Link to the bug: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1377653
You should start checking EDID on the video side and ELD on the audio side. ALSA driver shows the connection and ELD status in proc files and control elements. If EDID is given, but ELD (or monitor connection state) isn't, usually it's a video driver problem, e.g. the audio register bit isn't set properly.
Takashi
participants (2)
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samuelchemla＠orange.fr -
Takashi Iwai