Hi, during debugging ALSA's usb audio driver, it's found out that there are devices with insuccessive alternate settings.
for example, m-audio's quattro usb audio has audio streaming descriptors jumping from altset 0 to 4 or 3. apparently, usb_set_interface() sends the array index instead of the actual altset value. the attached patch fixes this behavior. Takashi
usb-altset.dif
Description: Binary data
