• Arvind Sankar's avatar
    ALSA: usb-audio: Apply sample rate quirk for Audioengine D1 · 93f9d1a4
    Arvind Sankar authored
    The Audioengine D1 (0x2912:0x30c8) does support reading the sample rate,
    but it returns the rate in byte-reversed order.
    
    When setting sampling rate, the driver produces these warning messages:
    [168840.944226] usb 3-2.2: current rate 4500480 is different from the runtime rate 44100
    [168854.930414] usb 3-2.2: current rate 8436480 is different from the runtime rate 48000
    [168905.185825] usb 3-2.1.2: current rate 30465 is different from the runtime rate 96000
    
    As can be seen from the hexadecimal conversion, the current rate read
    back is byte-reversed from the rate that was set.
    
    44100 == 0x00ac44, 4500480 == 0x44ac00
    48000 == 0x00bb80, 8436480 == 0x80bb00
    96000 == 0x017700,   30465 == 0x007701
    
    Rather than implementing a new quirk to reverse the order, just skip
    checking the rate to avoid spamming the log.
    Signed-off-by: default avatarArvind Sankar <nivedita@alum.mit.edu>
    Cc: <stable@vger.kernel.org>
    Link: https://lore.kernel.org/r/20200211162235.1639889-1-nivedita@alum.mit.eduSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    93f9d1a4
quirks.c 51.6 KB