[alsa-devel] Audio usb switch to alternate setting 0

Konstantinos Georgantas k.georgantas at samsung.com
Sun Jan 19 14:50:15 CET 2014

I am trying to control from the client side which Alternate Setting to 
use. Basically I would like to be able to switch from Alternate Setting 
0 to 1 and vice versa so that I am not receiving any set interface 
requests in the meantime. From the audio class 2.0 documentation I 
understand that I should be able to do something like this by using the 
active alternate setting control, and here comes my main problem.

When I generate an interrupt to the interrupt endpoint I should expect a 
GET request which I never see in the host side (hope I am right here).

Here comes the interrupt:
interrupt->bInfo          = 0x00;
interrupt->bAttribute  = 0x01;
interrupt->wValue       = 0x0100;
interrupt->wIndex       = 0x0004;

Could you please tell me if such a functionality is supported and how 
the interrupt should look like?

Thank you,

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