[Sound-open-firmware] [PTACH RFC 0/5] Add switch widget for loopback

[Pierre-Louis Bossart]

On 5/31/18 12:37 PM, Ranjani Sridharan wrote:
> On Thu, 2018-05-31 at 07:55 -0500, Pierre-Louis Bossart wrote:
>> On 5/30/18 9:08 PM, Pan, Xiuli wrote:
>>>
>>>
>>> On 5/30/2018 21:06, Pierre-Louis Bossart wrote:
>>>> On 5/30/18 4:51 AM, Xiuli Pan wrote:
>>>>> From: Pan Xiuli <xiuli.pan at linux.intel.com>
>>>>>
>>>>> Have some clean up for the code may used.
>>>>> Add some macros that are needed for the switch widget.
>>>>> TODO: Have the useable get/put function for the kcontrol.
>>>>>
>>>>> Pan Xiuli (5):
>>>>>     topology: mixer: Add CONTROLMIXER_MIN
>>>>>     topology: utils: Add kdapm macro for route with kcontrol
>>>>>     topology: m4: add switch widget
>>>>>     topology: sof: add pipeline loopback dai
>>>>>     topology: test: add loopback test topology
>>>>
>>>> What do you mean by "loopback"?
>>>> a) enabling capture on SSP with hardware LBM (LoopBackMode) -
>>>> mirroring the playback data?
>>>> b) enabling a capture-to-playback hostless pipeline - mirroring
>>>> the
>>>> capture data?
>>>
>>> I think the it should be the a). This will try to enable SSP
>>> driver
>>> loopback mode with a kcontrol.
>>
>> Not sure if it's wise to expose a kcontrol to users for what is
>> largely
>> a test capability - not to mention that you will not typically turn
>> this
>> on/off dynamically.
>> I'd suggest looking into using the topology+IPC to enable such custom
>> tests.
> 
> If it is not needed to turn this ON/OFF dynamically, then could we
> possibly just use a test FW with loopback mode enabled by default
> instead? That way we can avoid the extra work on the topology/driverside.

It's one token and one field in the IPC structure, with no framework 
change.
Compare that with requiring everyone to create a custom firmware when 
they want to test if the output looks correct...

> 
>>
>>
>>> Maybe we can try to make the b) also work.
>>>
>>> Thanks
>>> Xiuli
>>>>
>>>>
>>>>>
>>>>>    topology/m4/mixercontrol.m4               | 16 ++++--
>>>>>    topology/m4/switch.m4                     | 46
>>>>> +++++++++++++++
>>>>>    topology/m4/utils.m4                      |  4 ++
>>>>>    topology/sof/pipe-dai-loopback.m4         | 36 ++++++++++++
>>>>>    topology/sof/pipe-low-latency-capture.m4  |  3 +-
>>>>>    topology/sof/pipe-low-latency-playback.m4 |  2 +
>>>>>    topology/sof/pipe-pcm-media.m4            |  1 +
>>>>>    topology/sof/pipe-tone.m4                 |  2 +
>>>>>    topology/sof/pipe-volume-capture.m4       |  1 +
>>>>>    topology/sof/pipe-volume-playback.m4      |  1 +
>>>>>    topology/test/test-loopback-ssp.m4        | 94
>>>>> +++++++++++++++++++++++++++++++
>>>>>    topology/test/tplg-build.sh               |  2 +-
>>>>>    12 files changed, 201 insertions(+), 7 deletions(-)
>>>>>    create mode 100644 topology/m4/switch.m4
>>>>>    create mode 100644 topology/sof/pipe-dai-loopback.m4
>>>>>    create mode 100644 topology/test/test-loopback-ssp.m4
>>>>>
>>>
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>>
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