On 02/17/2016 01:52 PM, Mengdong Lin wrote:
On 02/15/2016 10:22 PM, Lars-Peter Clausen wrote:
On 02/15/2016 01:19 PM, Vaibhav Agarwal wrote:
Following patches are based on for-next branch from broonie tree.
First 2 patches include changes in existing soc, core framework
to prepare for adding support for dynamic DAI link addition/
removal
Patch 3 & 4 contains actual changes to enable dynamic DAI link
support
NOTE:
Currently, the code is tested on Pandaboad ES revB3 for playback
usecase.
Can you outline how exactly that would work?
Thanks,
- Lars
In Agarwal's use case, it seems a removable codec driver can be
registered after the sound card is registered. And the Pandaboard
machine driver need to add new BE links brought by the new codec
component, which will further trigger probing of the codec components.
How can the machine driver know a new codec component is registered
automatically?
Can we add a notification ops like "new_component" to a soc card?
A machine driver can implement this ops. So when a new component is
registered to the ASoC core, all instantiated soc cards can get notified
and the machine driver can check if the new component brings some new
links to the soc card in this ops. e.g. the Pandaboard machine driver
can add new BE links for the new codec.
Thanks
Mengdong
Sorry, I missed the case that the codec component can be still be
registered before the machine driver register the card. In this
situation, the machine driver cannot get the notification.
I wonder if the machine driver can still predefine these links but flag
them as "dynamically_registered". For such links, asoc core will not
abort instantiating the card, i.e. the sound card will be created even
if these links are not bound because lack of some DAIs (e.g. the DAIs of
the codec component not registered yet).
Then when the missing component is added, the ASOC core will
automatically check these the unbound links and bind them. When the
component is unregistered, ASoC will try to remove the affected links
and then remove the components.
Thus we may not need add new APIs or let the machine driver monitor when
the codec component is registered.
Thanks
Mengdong
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