ALSA: usb-audio - Fix non-continuous rate detection

The detection of non-continuous rates (given via rate tables) isn't
processed properly (e.g. for type II).

This patch fixes and simplifies the detection code.

Tested-by: Joris van Rantwijk <jorispubl@xs4all.nl>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 9 insertions, 8 deletions

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 2ab83129d9b..80863093d2c 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2524,7 +2524,6 @@ static int parse_audio_format_rates(struct snd_usb_audio *chip, struct audioform
                  * build the rate table and bitmap flags
                  */
                 int r, idx;
-                unsigned int nonzero_rates = 0;
 
                 fp->rate_table = kmalloc(sizeof(int) * nr_rates, GFP_KERNEL);
                 if (fp->rate_table == NULL) {
@@ -2532,24 +2531,26 @@ static int parse_audio_format_rates(struct snd_usb_audio *chip, struct audioform
                         return -1;
                 }
 
-                fp->nr_rates = nr_rates;
-                fp->rate_min = fp->rate_max = combine_triple(&fmt[8]);
+                fp->nr_rates = 0;
+                fp->rate_min = fp->rate_max = 0;
                 for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
                         unsigned int rate = combine_triple(&fmt[idx]);
+                        if (!rate)
+                                continue;
                         /* 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;
-                        nonzero_rates |= rate;
-                        if (rate < fp->rate_min)
+                        fp->rate_table[fp->nr_rates] = rate;
+                        if (!fp->rate_min || rate < fp->rate_min)
                                 fp->rate_min = rate;
-                        else if (rate > fp->rate_max)
+                        if (!fp->rate_max || rate > fp->rate_max)
                                 fp->rate_max = rate;
                         fp->rates |= snd_pcm_rate_to_rate_bit(rate);
+                        fp->nr_rates++;
                 }
-                if (!nonzero_rates) {
+                if (!fp->nr_rates) {
                         hwc_debug("All rates were zero. Skipping format!\n");
                         return -1;
                 }