On Tue, 08 Dec 2015 09:38:31 +0100, Vinod Koul wrote:
On Tue, Dec 08, 2015 at 08:52:10AM +0100, Takashi Iwai wrote:
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.
Okay got it now, that is how my 3 limit for MST is coming from as we have 3 CVTs so we can actually stream to only 3 devices per port although someone may theoretically connect 64!
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.
And how many PCMs are you proposing for MST?
5 for Intel, i.e. Nconv * 2 - 1. This could be even Nconv, but we provide the reserved slots just for the compatible behavior that assumes the static pin/slot assignment.
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.
Well am not supporting MST at the moment. How is legacy handling this, how do you report jack for 64 X 3 devices :)
Or, are you reporting jack for PCMs based on connection to pin/device, I think latter.
Yes, the jack reporting is for PCM in this case, which is I mentioned in the first reply: it's not about pin but PCM.
But then you would hit limit of PCMs, I assume you maybe doing 9 PCMs for this, so if someone connects 10th device we won't report it's jack?
The jack reporting is done actually at the time the audio is enabled/disabled. And at this moment, the PCM assignment is assured as well. So, to user-space, only the actually usable devices are exposed no matter how many devices are plugged.
Takashi