> -----Original Message----- > From: David Henningsson [mailto:david.henningsson@xxxxxxxxxxxxx] > Sent: Thursday, October 22, 2015 4:53 PM > To: Yang, Libin; Raymond Yau; Takashi Iwai > Cc: airlied@xxxxxxxx; tanuk@xxxxxx; ALSA Development Mailing List; > Girdwood, Liam R; Lin, Mengdong > Subject: Re: DP1.2 MST audio support discussion > > > > On 2015-10-22 09:40, Yang, Libin wrote: > > > >>>>>> From: Raymond Yau [mailto:superquad.vortex2@xxxxxxxxx] > >>>>>> Sent: Friday, October 16, 2015 8:33 AM > >>>>>> To: Takashi Iwai > >>>>>> Cc: airlied@xxxxxxxx; tanuk@xxxxxx; David Henningsson; Yang, > Libin; > >>>> Lin, > >>>>>> Mengdong; Girdwood, Liam R; ALSA Development Mailing List > >>>>>> Subject: Re: 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". > > > > OK, I see. Thanks. I will not change the jack kctl name. > > BTW, the PCM number will be the same as converter, which means > > it will be 3 on Intel platforms. > > I'll try to explain my suggestion (which I believe Takashi's buying too) > one more time then: > > First, when a monitor is plugged in, we need to dynamically assign this > monitor to five PCM devices. I believe this scheme will be best: > > For a monitor at pin nid 0x05, dev index 0, it will prefer PCM 3. > For a monitor at pin nid 0x06, dev index 0, it will prefer PCM 7. > For a monitor at pin nid 0x07, dev index 0, it will prefer PCM 8. > For a monitor at dev index 1 (any pin), it will prefer PCM 9. > For a monitor at dev index 2 (any pin), it will prefer PCM 10. > > For monitors at dev indices > 2 (can that happen?), or if the PCM is > already assigned to something else, try PCMs in this order: 9, 10, 3, 7, > 8. > (Subject to discussion perhaps, I don't think the order matters too > much, because conflicts will be rare in practice.) Oh, it seems my understand is wrong. OK, so the pcm number will be: Pin number + max (device entry number per pin) - 1. For example, on intel platform, it is 5. > > The jack and ELD kctls - one per PCM device - will follow what monitor > the PCM is currently assigned to. (kctls belonging to a PCM device that > is unassigned will report presence_detect=0 and eld_valid=0.) It makes sense. This should be mostly friendly to userspace. I will do it. > > Then, at playback open time, a free converter node will be dynamically > assigned to the PCM. If there are no free converter nodes, return - > EBUSY. Yes, this is what I think. > > Now remains the case when an unassigned PCM is opened. This needs > additional thinking, but the more backwards compatibility we can keep > for this case, the better. But I'm not sure about how possible it is to > let streams "freewheel" in this new DSP MST world? Do you mean playing on unassigned PCM should work as the monitor is connected? I remember Takashi mentioned disconnecting monitor when playback should trigger stop PCM. This case should follow the same policy and return -ENODEV or -EINVAL? > > >> 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. > > > > My current thought is to expose the same jack kctls (same number > and > > same name) to userspace while we will create hda_jack_tbl for each > device > > entry. When pcm is bound to the device entry, the corresponding > > jack kctl will be bound to the device entry. > > -- > David Henningsson, Canonical Ltd. > https://launchpad.net/~diwic _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
