On 2015-10-22 08:56, Yang, Libin wrote:
-----Original Message----- From: David Henningsson [mailto:david.henningsson@canonical.com] Sent: Thursday, October 22, 2015 2:52 PM To: Yang, Libin; Raymond Yau; Takashi Iwai Cc: airlied@linux.ie; tanuk@iki.fi; Lin, Mengdong; Girdwood, Liam R; ALSA Development Mailing List Subject: Re: [alsa-devel] DP1.2 MST audio support discussion
On 2015-10-22 03:31, Yang, Libin wrote:
Hi Raymond,
From: Raymond Yau [mailto:superquad.vortex2@gmail.com] Sent: Friday, October 16, 2015 8:33 AM To: Takashi Iwai Cc: airlied@linux.ie; tanuk@iki.fi; David Henningsson; Yang, Libin;
Lin,
Mengdong; Girdwood, Liam R; ALSA Development Mailing List Subject: Re: [alsa-devel] DP1.2 MST audio support discussion
Do it mean that only one DP MST port and no HDMI port on the
same graphic
card ?
No.
If there is only one HDMI and one Display Port, this mean that there are two pin complexes How about the name of jack detection kctl of three Display Port monitors which are created on the same pin complex but different dev_index ?
For the jack name, what do you think if we change to "HDMI/DP, pin=n, dev=m" format? Will it impact on pulseaudio?
Yes, it will impact PulseAudio. It will require changes to files in
http://cgit.freedesktop.org/pulseaudio/pulseaudio/tree/src/modules/ alsa/mixer/paths
So does this mean we should not change the name "HDMI/DP,pcm=3 Jack" to "HDMI/DP,pin=n, dev=m Jack", otherwise the old PA will not work with the new driver?
Yes. And I don't understand why you need to do it, either - if you have three display port monitors on one pin, then they will all get different PCMs (8, 9 and 10), and they will signal their Jack status through "HDMI/DP,pcm=8 Jack", "HDMI/DP,pcm=9 Jack" and "HDMI/DP,pcm=10 Jack".
Given that my proposed mapping algorithm will never change pin to PCM mapping (unless you have two displayport outputs and use MST on both), I think we can get away with not exposing the actual pin to userspace. And should this later become necessary, we can add a separate kctl for that.