From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH v3 14/15] ASoC: hdac_hdmi: Add jack reporting for user space Date: Tue, 08 Dec 2015 08:52:10 +0100 Message-ID: References: <1449523078-4311-1-git-send-email-subhransu.s.prusty@intel.com> <1449523469-4395-1-git-send-email-subhransu.s.prusty@intel.com> <1449523469-4395-14-git-send-email-subhransu.s.prusty@intel.com> <20151208063135.GN1854@localhost> <20151208074216.GO1854@localhost> 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 74CA6261785 for ; Tue, 8 Dec 2015 08:52:12 +0100 (CET) In-Reply-To: <20151208074216.GO1854@localhost> 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: Vinod Koul Cc: patches.audio@intel.com, alsa-devel@alsa-project.org, broonie@kernel.org, "Subhransu S. Prusty" , lgirdwood@gmail.com List-Id: alsa-devel@alsa-project.org On Tue, 08 Dec 2015 08:42:16 +0100, Vinod Koul wrote: > > On Tue, Dec 08, 2015 at 07:38:46AM +0100, Takashi Iwai wrote: > > On Tue, 08 Dec 2015 07:31:36 +0100, > > Vinod Koul wrote: > > > > > > On Mon, Dec 07, 2015 at 05:18:06PM +0100, Takashi Iwai wrote: > > > > On Mon, 07 Dec 2015 22:24:28 +0100, > > > > > + sprintf(jack_name, "HDMI/DP, Pin=%d Jack", pin->nid); > > > > > > > > Such a name makes sense only to be compatible for PA, and then this > > > > string isn't compatible. Note that it's not about pin but for PCM > > > > stream. You may wonder why it matters -- see the whole discussion on > > > > MST support. > > > > > > So in our case we have added only one PCM Backend in DSP. In codec we have > > > one DAI supported, thus creating a DAIlink > > > > > > The Codec DAI is mapped to a stream which we fix to a CVT. Future we > > > will add two more streams which are mapped to other two CVTs. > > > > > > We use MUX controls to allow user to specfiy how CVT and PINs are connected > > > togther, this way we can route stream to any pin. > > > > > > Extending this concept, behind a pin for MST there may be different 'ports', > > > right? Shouldn't that be another mux configuration :) So we can treat three > > > streams coming to codec to be routed to any pin and then any port. Since we > > > have only 3 CVTs we will have only 3 streams... > > > > You can't do that easily. Remember that you may connect up to 64 > > different devices at the same time per pin, and this can switch on the > > fly. How would you implement a MUX? > > somehow I was under impression that it is 3.. Btw even if 64 devices can be > connected how many can we render to? That's what I meant below. Although you can may connect quite a lot of devices, the number of devices that can be actually output at the same time is limited, actually equal with the number of converters. > > Though, the max number of converters is limited, thus what you can > > actually use is defined by this constraint. Due to this, we'll likely > > manage MST for the legacy HDA by assigning MST devs dynamically to > > pins in a certain procedure to make things compatible. > > but how many MST devs are you going to create? This is exactly the point: for the legacy HDA, instead of creating the entry for each MST devices, they are assigned dynamically to PCM at activation. So the number of devices exposed to user-space is limited -- or better to say, user-space won't notice the difference. > > > Back on present :), what do you recommend for us for jack name. > > > > Depends on your purpose. If you want to keep it compatible, then use > > the compatible string. > > Since compatible string would mean specfying PCM, which we don;t know and is > per machine driver dailink defination, we would go ahead with logical > "HDMI/DP, Pin=%d Jack" names. But then it makes little sense. Multiple MST devices can be on the same pin. Takashi