On Tue, 22 Dec 2015 09:47:12 +0100, Libin Yang wrote: > > Hi Takashi, > > On 11/09/2015 11:15 PM, Takashi Iwai wrote: > > On Mon, 09 Nov 2015 16:00:01 +0100, > > Yang, Libin wrote: > >> > >> Hi Takashi, > >> > >>> -----Original Message----- > >>> From: Takashi Iwai [mailto:tiwai@xxxxxxx] > >>> Sent: Monday, November 09, 2015 3:59 PM > >>> To: Libin Yang > >>> Cc: alsa-devel@xxxxxxxxxxxxxxxx; mengdong.lin@xxxxxxxxxxxxxxx; Yang, > >>> Libin > >>> Subject: Re: [RFC PATCH 0/2] ALSA: hda - DP MST audio for > >>> Jack support > >>> > >>> On Wed, 04 Nov 2015 07:23:14 +0100, > >>> Libin Yang wrote: > >>>> > >>>> > >>>> On 11/04/2015 12:49 AM, Takashi Iwai wrote: > >>>>> On Tue, 03 Nov 2015 09:42:54 +0100, > >>>>> libin.yang@xxxxxxxxxxxxxxx wrote: > >>>>>> > >>>>>> From: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > >>>>>> > >>>>>> This is the patch set for Jack support for DP MST audio > >>>>>> > >>>>>> Libin Yang (2): > >>>>>> ALSA: hda - jack support DP MST audio > >>>>>> ALSA: hda - hdmi audio add dynamically jack binding to pin > >>>>> > >>>>> I'm somehow confused by this patch series. > >>>>> Is the unsolicited event handling itself changed for MST? I mean, you > >>>>> cannot know which MST dev# is given beforehand, while you seem > >>> trying > >>>>> to assign such a number to the jack object. > >>>> > >>>> Oh, sorry I forgot to mention that we only operate on device entry 0 > >>>> so far in the code. It's misleading. > >>>> > >>>> These patches don't operate on MST audio. The full MST audio driver > >>>> support will be implemented in the later patches. The patches help to > >>>> prepare supporting MST audio. > >>>> > >>>> The purpose of the patches is try to dynamically attach the Jack. > >>> > >>> Well, only judging from the quick glance, I don't buy this strategy, > >>> sorry. Currently for HDMI/DP, the jack is for PCM, not for pin. > >>> Namely, user-space watches the jack notification to judge whether the > >>> corresponding PCM is available or not. You're trying to change this > >>> scheme completely. > >> > >> The patch is to make sure the jack is bound to PCM statically. > >> This patch is needed because in old code, it will create jack with: > >> for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) { > >> ... > >> err = generic_hdmi_build_jack(codec, pin_idx); > >> ... > >> } > >> Which means the jack is created based on pin number and pin_idx. > >> As a pin is bound statically to the PCM, the jack is statically bound to PCM. > > > > OK, so far, so good. > > > >> Now we are using the dynamic pcm bound. If we use the old code to > >> create the jack, the jack will be bound to pin. So we need the patch, > >> which will use the new code: > >> for (pcm_idx = 0; pcm_idx < spec-> pcms_used; pcm_idx++) { > >> ... > >> err = generic_hdmi_build_jack(codec, pcm_idx); > >> ... > >> } > >> which makes sure that the jack is bound to PCM (jack[0] is bound > >> to pcm[0], jack[1] is bound to pcm[1] and so on). > >> > >> If there is no monitor, no pin is bound to the PCM. > >> So no pin is bound to the Jack. When there is a monitor connected, > >> the pin is bound to a proper PCM. So we should bind the PCM's jack > >> to the pin. > >> > >> For example, jack0 is bound to the PCM 3 (the first jack is bound > >> to the first PCM statically). When a monitor is connected to pin 5, > >> PCM 3 will be assigned to the pin. We need bind jack 0 to pin 5. > >> When monitor is disconnected, we must unbind the jack 0 from pin 5. > >> These operation are done in function > >> snd_hda_jack_bind/ snd_hda_jack_unbind. > > > > Then we shouldn't use the hda_jack.c code at all for HDMI/DP. > > For HDMI/DP with the dynamic PCM binding, the only state to check is > > its PCM assignment. It doesn't have to issue the jack state check via > > HDA verb at all. This should make things a lot easier. > > I'm now porting the jack supporting for MST audio. The code on > hdmi-jack branch will create jack differently based codec_has_acomp() > condition. Does this mean MST Jack binding will handle both situation? Ideally, yes. > My idea is: > 1. Add struct snd_jack *jack[] member in hdmi_spec. > 2. Create the jack based on PCM > 3. Assign spec->jack[i] to per_pin->acomp_jack when pin is connected. > > This should be OK for codec_has_acomp sitation. Hrm, not really. As already discussed, a jack is associated to each PCM, and notified plug/unplug when it's assigned / unassigned. That is, you don't have to keep extra jack array. When a PCM is assigned or unassigned, simply notify per_pin->acomp_jack of that PCM. That's all. So there shouldn't be too many difference from the current situation. > But what about the > other situation? The other situation still uses the hda_jack_tbl and > etc. So we still need handle hda jack if we want to reuse the current > code. For other, it's similar. The jack is associated with PCM, which is virtually bound with per_pin. And when it's assigned / unassigned, call it with the given per_pin->pin_nid. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
