ALSA: usb-audio: Set up (implicit) sync for Saffire 6

commit e0469d6581aecb0e34e2ec64f39f88e6985cc52f upstream.

Focusrite Saffire 6 has fixed audioformat quirks with multiple
endpoints assigned to a single altsetting.  Unfortunately the generic
parser couldn't detect the sync endpoint correctly as the implicit
sync due to the missing EP attribute bits.  In the former kernels, it
used to work somehow casually, but it's been broken for a while after
the large code change in 5.11.

This patch cures the regression by the following:
- Allow the static quirk table to provide the sync EP information;
  we just need to fill the fields and let the generic parser skipping
  parsing if sync_ep is already set.
- Add the sync endpoint information to the entry for Saffire 6.

Fixes: 7b0efea4baf0 ("ALSA: usb-audio: Add missing ep_idx in fixed EP quirks")
Reported-and-tested-by: André Kapelrud <a.kapelrud@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220606160910.6926-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 00c1f2960ab7181ef7551385e56071aef7e88c62..b6cd43c5ea3e631b1ec86f058b8320b930ac5a7f 100644 (file)
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -291,6 +291,9 @@ int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
        bool is_playback;
        int err;
 
+       if (fmt->sync_ep)
+               return 0; /* already set up */
+
        alts = snd_usb_get_host_interface(chip, fmt->iface, fmt->altsetting);
        if (!alts)
                return 0;

diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index 78eb41b621d63fab9fd7381fabaae33e2ce79964..4f56e1784932a29e21d92ee6508b6b54030d7164 100644 (file)
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2658,7 +2658,12 @@ YAMAHA_DEVICE(0x7010, "UB99"),
                                        .nr_rates = 2,
                                        .rate_table = (unsigned int[]) {
                                                44100, 48000
-                                       }
+                                       },
+                                       .sync_ep = 0x82,
+                                       .sync_iface = 0,
+                                       .sync_altsetting = 1,
+                                       .sync_ep_idx = 1,
+                                       .implicit_fb = 1,
                                }
                        },
                        {