From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: Problems with the DP MST audio support patchset Date: Fri, 31 Mar 2017 23:31:24 +0200 Message-ID: References: <6800ee6e-31c2-b5eb-fbb2-6826d8c66dc9@pa-w.de> <96A12704CE18D347B625EE2D4A099D19524850F3@SHSMSX103.ccr.corp.intel.com> <63a71394-1cd4-e3e3-7364-37c2da90c791@pa-w.de> <96A12704CE18D347B625EE2D4A099D19524854BD@SHSMSX103.ccr.corp.intel.com> <49ff23f3-7c58-abf1-f1ff-87822f0b0585@pa-w.de> <96A12704CE18D347B625EE2D4A099D19524866B0@SHSMSX103.ccr.corp.intel.com> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 059D52668F6 for ; Fri, 31 Mar 2017 23:31:25 +0200 (CEST) In-Reply-To: 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: Pascal Wichmann Cc: "Yang, Libin" , Libin Yang , "alsa-devel@alsa-project.org" List-Id: alsa-devel@alsa-project.org On Fri, 31 Mar 2017 21:04:37 +0200, Pascal Wichmann wrote: > > Hi all, > > > I guess the digital-7.1 corresponds to HBR, and it's a special > > setup. Meanwhile 5.1 output he has tried is likely the LPCM, so > > both are in a completely differently manner. > Thank you, that sounds like a good explanation for my first issue. > > > For the other problem, that seems to be some kind of HDMI handshake > related issue to me. > I have done some more research and found similar > problems like [0]. Their solution to enable a pulseaudio loopback seemed > to improve the situation at first; at least during the last two hours, > the problem did not occur as often as it did before (without explicitly > provoking it), but it occurred though. > > In addition, I have disabled the power save options of the snd_hda_intel > module: > > options snd_hda_intel power_save=0 power_save_controller=N > This however does not seem to have any impact on the problem at all. > > I have also found a way to reliably reproduce the problem by muting and > immediately unmuting the output in alsamixer having some audio running > - -- this way, the output gets silenced for a few seconds a moment after > the unmuting almost always. > > Is the above solution using the pulseaudio loopback module not enough to > prevent handshake issues? Do handshake issues sound suitable at all? Do > you have any other ideas where the problem may lies? It's a general problem with many digital receivers. When the stream stops, a digital receiver turn itself off until it re-receives a new stream. And this on/off takes a few seconds. Thus, you must not stop the stream, but you'd need to keep sending the silent stream even if you stop a playback. Takashi