[PATCH 3.18 097/108] ALSA: usb-audio: Fix implicit fb endpoint setup by quirk
From: Greg Kroah-Hartman
Date: Mon Feb 18 2019 - 09:12:54 EST
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Manuel Reinhardt <manuel.rhdt@xxxxxxxxx>
commit 2bc16b9f3223d049b57202ee702fcb5b9b507019 upstream.
The commit a60945fd08e4 ("ALSA: usb-audio: move implicit fb quirks to
separate function") introduced an error in the handling of quirks for
implicit feedback endpoints. This commit fixes this.
If a quirk successfully sets up an implicit feedback endpoint, usb-audio
no longer tries to find the implicit fb endpoint itself.
Fixes: a60945fd08e4 ("ALSA: usb-audio: move implicit fb quirks to separate function")
Signed-off-by: Manuel Reinhardt <manuel.rhdt@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/pcm.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -311,6 +311,9 @@ static int search_roland_implicit_fb(str
return 0;
}
+/* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
+ * applies. Returns 1 if a quirk was found.
+ */
static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
struct usb_device *dev,
struct usb_interface_descriptor *altsd,
@@ -370,7 +373,7 @@ add_sync_ep:
subs->data_endpoint->sync_master = subs->sync_endpoint;
- return 0;
+ return 1;
}
static int set_sync_endpoint(struct snd_usb_substream *subs,
@@ -395,6 +398,10 @@ static int set_sync_endpoint(struct snd_
if (err < 0)
return err;
+ /* endpoint set by quirk */
+ if (err > 0)
+ return 0;
+
if (altsd->bNumEndpoints < 2)
return 0;