On Thu, Mar 3, 2016 at 6:37 PM, Clemens Ladisch clemens@ladisch.de wrote:
Puneet Sharma wrote:
As per my understanding, when the above interrupt endpoint is transferred to host in response to Interrupt IN request, the host should send me a
GET
CUR volume class-specific request to further qualify the cause of
interrupt.
However, I am not getting any class-specific request from host in
response
to the status interrupt transferred to host.
My query is do i need to implement a mixer interface in the uac2 kernel driver to get the request or i am doing something wrong in the process.
You must not send a notification for a unit ID that does not exist, so you must implement the mixer interface.
I have used a feature unit descriptor in the gadget driver with volume control. The Feature unit is inserted between Input and output terminal having a unique Unit ID.
And you will get a request to read the control's current volume only if some application that cares about the value (e.g., alsamixer) actually happens to be running on the host.
Yes, I understand your point now.
After running alsamixer on host, I am able to send volume request to device as well get volume request from host in response to status interrupt.
Regards, Clemens