[PATCH 4.14 010/237] ALSA: usb-audio: Apply sample rate quirk for Audioengine D1

Greg Kroah-Hartman
2020-02-27T13:52:36Z

From: Arvind Sankar <nivedita@alum.mit.edu>

commit 93f9d1a4ac5930654c17412e3911b46ece73755a upstream.

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: Arvind Sankar <nivedita@alum.mit.edu>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200211162235.1639889-1-nivedita@alum.mit.edu
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/usb/quirks.c | 1 +
1 file changed, 1 insertion(+)

--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -1151,6 +1151,7 @@ bool snd_usb_get_sample_rate_quirk(struc
case USB_ID(0x1de7, 0x0014): /* Phoenix Audio TMX320 */
case USB_ID(0x1de7, 0x0114): /* Phoenix Audio MT202pcs */
case USB_ID(0x21B4, 0x0081): /* AudioQuest DragonFly */
+ case USB_ID(0x2912, 0x30c8): /* Audioengine D1 */
return true;
}
return false;