1 files changed, 17 insertions, 3 deletions

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index c7b902358b7b..8db0374e10d5 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1083,6 +1083,8 @@ static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int peri
         } else
                 urb_packs = 1;
         urb_packs *= packs_per_ms;
+        if (subs->syncpipe)
+                urb_packs = min(urb_packs, 1U << subs->syncinterval);
 
         /* decide how many packets to be used */
         if (is_playback) {
@@ -2124,8 +2126,8 @@ static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct s
                 fp = list_entry(p, struct audioformat, list);
                 snd_iprintf(buffer, "  Interface %d\n", fp->iface);
                 snd_iprintf(buffer, "    Altset %d\n", fp->altsetting);
-                snd_iprintf(buffer, "    Format: %#x (%d bits)\n",
-                            fp->format, snd_pcm_format_width(fp->format));
+                snd_iprintf(buffer, "    Format: %s\n",
+                            snd_pcm_format_name(fp->format));
                 snd_iprintf(buffer, "    Channels: %d\n", fp->channels);
                 snd_iprintf(buffer, "    Endpoint: %d %s (%s)\n",
                             fp->endpoint & USB_ENDPOINT_NUMBER_MASK,
@@ -2661,7 +2663,7 @@ static int parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
         struct usb_interface_descriptor *altsd;
         int i, altno, err, stream;
         int format;
-        struct audioformat *fp;
+        struct audioformat *fp = NULL;
         unsigned char *fmt, *csep;
         int num;
 
@@ -2734,6 +2736,18 @@ static int parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
                         continue;
                 }
 
+                /*
+                 * Blue Microphones workaround: The last altsetting is identical
+                 * with the previous one, except for a larger packet size, but
+                 * is actually a mislabeled two-channel setting; ignore it.
+                 */
+                if (fmt[4] == 1 && fmt[5] == 2 && altno == 2 && num == 3 &&
+                    fp && fp->altsetting == 1 && fp->channels == 1 &&
+                    fp->format == SNDRV_PCM_FORMAT_S16_LE &&
+                    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
+                                                        fp->maxpacksize * 2)
+                        continue;
+
                 csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
                 /* Creamware Noah has this descriptor after the 2nd endpoint */
                 if (!csep && altsd->bNumEndpoints >= 2)