[ALSA] usb-audio: work around wrong frequency in CM6501 descriptors

The C-Media CM6501 chip's descriptors say that altsetting 5 supports
48 kHz, but it actually plays at 96 kHz.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 3d7f36f..5f160ee 100644 (file)
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2471,7 +2471,13 @@ static int parse_audio_format_rates(struct snd_usb_audio *chip, struct audioform
                fp->nr_rates = nr_rates;
                fp->rate_min = fp->rate_max = combine_triple(&fmt[8]);
                for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
-                       unsigned int rate = fp->rate_table[r] = combine_triple(&fmt[idx]);
+                       unsigned int rate = combine_triple(&fmt[idx]);
+                       /* C-Media CM6501 mislabels its 96 kHz altsetting */
+                       if (rate == 48000 && nr_rates == 1 &&
+                           chip->usb_id == USB_ID(0x0d8c, 0x0201) &&
+                           fp->altsetting == 5 && fp->maxpacksize == 392)
+                               rate = 96000;
+                       fp->rate_table[r] = rate;
                        if (rate < fp->rate_min)
                                fp->rate_min = rate;
                        else if (rate > fp->rate_max)