Hi Takashi, > -----Original Message----- > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > Sent: Wednesday, November 11, 2015 4:06 PM > To: Yang, Libin > Cc: 'David Henningsson'; Lin, Mengdong; 'Raymond Yau'; 'airlied@xxxxxxxx'; > 'tanuk@xxxxxx'; 'ALSA Development Mailing List'; Girdwood, Liam R; Lu, > Han; Nikula, Jani > Subject: Re: DP1.2 MST audio support discussion > > On Wed, 11 Nov 2015 08:58:29 +0100, > Yang, Libin wrote: > > > > > > > -----Original Message----- > > > From: Yang, Libin > > > Sent: Wednesday, November 11, 2015 10:04 AM > > > To: David Henningsson; Takashi Iwai > > > Cc: Lin, Mengdong; Raymond Yau; airlied@xxxxxxxx; tanuk@xxxxxx; ALSA > > > Development Mailing List; Girdwood, Liam R; Lu, Han; Nikula, Jani > > > Subject: RE: DP1.2 MST audio support discussion > > > > > > > > > > -----Original Message----- > > > > From: David Henningsson > [mailto:david.henningsson@xxxxxxxxxxxxx] > > > > Sent: Tuesday, November 10, 2015 3:45 PM > > > > To: Yang, Libin; Takashi Iwai > > > > Cc: Lin, Mengdong; Raymond Yau; airlied@xxxxxxxx; tanuk@xxxxxx; > ALSA > > > > Development Mailing List; Girdwood, Liam R; Lu, Han; Nikula, Jani > > > > Subject: Re: DP1.2 MST audio support discussion > > > > > > > > > > > > > > > > On 2015-11-10 07:46, Yang, Libin wrote: > > > > > Hi David, > > > > > > > > > > > > > > >> -----Original Message----- > > > > >> From: David Henningsson > > > [mailto:david.henningsson@xxxxxxxxxxxxx] > > > > >> Sent: Thursday, November 05, 2015 5:07 PM > > > > >> To: Yang, Libin; Takashi Iwai > > > > >> Cc: Lin, Mengdong; Raymond Yau; airlied@xxxxxxxx; tanuk@xxxxxx; > > > ALSA > > > > >> Development Mailing List; Girdwood, Liam R; Lu, Han; Nikula, > Jani > > > > >> Subject: Re: DP1.2 MST audio support discussion > > > > >> > > > > >> > > > > >> > > > > >> So I'm asking my question again. What would happen (on Intel > > > > hardware), > > > > >> if you stream audio to a converter node on the audio codec, and > > > there > > > > is > > > > >> no pin node connected to that converter node? > > > > > > > > > > I changed the audio driver and did the test today. The test is: > > > > > 1. Pin 5 connect to converter 2 and playback, there is sound from > pin > > > 5. > > > > > 2. Pin 5 connect to converter 2 (no other pin is connected to cvt2), > no > > > > sound. > > > > > 3. Pin 5 connect back to cvt 2, there is sound, playback is normal. > > > > > > > > > > And in step 2, the playback is still ongoing but no sound is out from > > > any > > > > pin. > > > > > > > > Sounds good to me, thanks for testing. Is this workaround > something > > > we > > > > could utilize in order to not break userspace? (This is a question for > > > > both you and Takashi.) > > > > > > > > What we'll end up is essentially three types of objects: > > > > > > > > * PCM device (5 devices, 3,7,8,9,10) > > > > - all five devices are allocated when the driver initializes > > > > > > This should be for Intel platform, right? The actually number > > > should be: > > > pin number + device entry number - 1. > > > On intel platform, pin_num = 3, dev_num = 3, so it will be 5. > > > > > > > - all kcontrols are always bound to the PCM device (jack kctl, eld > > > > kctl, iec958 kctls etc) > > > > > > Sure, I agree on it. > > > > > > > > > > > * Monitor (pin + MST index) > > > > - dynamically bound to a PCM at monitor plug-in time, according > to a > > > > scheme that maximises the possibility for a monitor to always end > up at > > > > the same PCM (as specified in earlier emails) > > > > > > > > * Converter node (3 nodes for Intel hardware) > > > > - dynamically bound to a PCM at playback open time (regardless > of > > > > whether the PCM has a monitor or not) > > > > > > If so, we still need use converter on codec. This means we can't turn > > > off the power well in i915. > > > > > > To save the power, i915 suggests that if no monitor is connected, > > > we should not use the HDMI codec. This means open a PCM with > > > no pin attached will fail. Disconnecting monitor when the > corresponding > > > PCM is playback will trigger stop PCM. > > > > > > To help move to the new method smoothly, I will add a flag. > > > User can decide whether to use the aggressive power saving > > > solution or not. > > > > In hdmi_pcm_open(), it will judge whether pin_idx is valid, > > if not it will return -EINVAL. So for dynamic PCM assignment, > > open will fail if no monitor is connected. > > > > If we want to support open on PCM without monitor, many > > code must be rewrited. And it seems open a PCM without > > monitor is not a good behavior. As Raymond said in previous > > email, For alt analog playback device , it return EBUSY when > > DAC of HP is not available. I think for HDMI audio we can > > have the aligned behavior? And -ENODEV may be better. > > Libin, it's why I've been repeated asking to split the patches, > instead of posting a big iron patch. Then we can test and evaluate > whether this part is really working in general. Yes, I understand. :) The patches are being split. Suppose these 2 days patches should be ready for review. Regards, Libin > > > Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
