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

[Ranjani Sridharan]

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. 

> 
> 
> > 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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