• Eldad Zack's avatar
    ALSA: usb-audio: UAC2: support read-only freq control · 1dc669fe
    Eldad Zack authored
    Some clocks might be read-only, e.g., external clocks (see also
    UAC2 4.7.2.1).
    
    In this case, setting the sample frequency will always fail
    (even if the rate is equal to the current clock rate),
    therefore do not write, but read the value and compare to the
    requested rate.
    If the clock is read only, avoid reading it twice.
    
    If it doesn't match, return -ENXIO since the clock is invalid for
    this configuration.
    Signed-off-by: default avatarEldad Zack <eldad@fogrefinery.com>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    1dc669fe
clock.c 11.5 KB