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>

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 2ab8312..8086309 100644 (file)
--- 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;
                }