From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Henningsson Subject: Re: DP1.2 MST audio support discussion Date: Thu, 22 Oct 2015 09:27:51 +0200 Message-ID: <56288FF7.9030400@canonical.com> References: <96A12704CE18D347B625EE2D4A099D1974C250@SHSMSX103.ccr.corp.intel.com> <561CA911.7070405@canonical.com> <96A12704CE18D347B625EE2D4A099D1974C304@SHSMSX103.ccr.corp.intel.com> <96A12704CE18D347B625EE2D4A099D1975281F@SHSMSX103.ccr.corp.intel.com> <56288783.1080503@canonical.com> <96A12704CE18D347B625EE2D4A099D19753A2D@SHSMSX103.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by alsa0.perex.cz (Postfix) with ESMTP id 350F12606F9 for ; Thu, 22 Oct 2015 09:27:46 +0200 (CEST) In-Reply-To: <96A12704CE18D347B625EE2D4A099D19753A2D@SHSMSX103.ccr.corp.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: "Yang, Libin" , Raymond Yau , Takashi Iwai Cc: "airlied@linux.ie" , "tanuk@iki.fi" , ALSA Development Mailing List , "Girdwood, Liam R" , "Lin, Mengdong" List-Id: alsa-devel@alsa-project.org 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. -- David Henningsson, Canonical Ltd. https://launchpad.net/~diwic