On Thu, Mar 3, 2016 at 6:37 PM, Clemens Ladisch <clemens@xxxxxxxxxx> 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 > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
