Re: [alsa-devel] [RFC PATCH] ucm: Add support for device positions

3 Jan 2017


      On 01/03/2017 04:21 PM, Vinod Koul wrote:
...
On Tue, Jan 03, 2017 at 02:09:18PM +0800, mengdong.lin@linux.intel.com wrote:
...
From: Mengdong Lin mengdong.lin@linux.intel.com
Users can provide prosition info of audio devices as a device value. This
will help the sound server to choose an audio devices from some candidates
based on the their locations and the status of the machine.
This is good thing to have but some bits are bit unclear to me atm. When you
say device, do you mean sound card?
No, the device here does not mean a sound card, but mean an I/O device 
like speaker or dmic, defined by 'SectionDevice'.
...
For me, position makes sense for dmics and speakers. So can you help me out
by understanding how we can describe these...
For example, if there are two DMICs, one is in the front and one on the 
back, we can define their positions as below:
SectionDevice."MainMIC" {
...
EnableSequence [
                ...
         ]
DisableSequence [
                 ...
         ]
Value {
                 Position "Front"
         }
}
SectionDevice."SecondaryMIC" {
...
EnableSequence [
    ...
    ]
DisableSequence [
    ...
    ]
Value {
    	Position "Back"
    }
}
Thanks
Mengdong