The PCM trigger callback is atomic, hence we must not call a function
like usb_set_interface() there. Calling it from there would lead to a
kernel Oops.
Fix it by moving the usb_set_interface() call to set_sync_endpoint().
Also, apply the snd_usb_set_interface_quirk() for consistency, too.
Tested-by: Keith Milner <kamilner@xxxxxxxxxxxxxxx>
Tested-by: Dylan Robinson <dylan_robinson@xxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/usb/pcm.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 3265155df1b5..380d7275d187 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -232,21 +232,6 @@ static int start_endpoints(struct snd_usb_substream *subs)
!test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
struct snd_usb_endpoint *ep = subs->sync_endpoint;
- if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
- subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
- err = usb_set_interface(subs->dev,
- subs->sync_endpoint->iface,
- subs->sync_endpoint->altsetting);
- if (err < 0) {
- clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
- dev_err(&subs->dev->dev,
- "%d:%d: cannot set interface (%d)\n",
- subs->sync_endpoint->iface,
- subs->sync_endpoint->altsetting, err);
- return -EIO;
- }
- }
-
dev_dbg(&subs->dev->dev, "Starting sync EP @%p\n", ep);
ep->sync_slave = subs->data_endpoint;
@@ -530,6 +515,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs,
subs->data_endpoint->sync_master = subs->sync_endpoint;
+ if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
+ subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
+ err = usb_set_interface(subs->dev,
+ subs->sync_endpoint->iface,
+ subs->sync_endpoint->altsetting);
+ if (err < 0)
+ return err;
+ dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
+ subs->sync_endpoint->iface,
+ subs->sync_endpoint->altsetting);
+ snd_usb_set_interface_quirk(dev);
+ }
+
return 0;
}
--
2.16.4
