ALSA: usb-audio: assume valid clock

If the interface can't report a clock's validity, assume that it's
valid.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-by: Vicente Joel <vicentejoel@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 10 insertions, 1 deletions

diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index 7754a1034545..075195e8661a 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -104,6 +104,15 @@ static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
         int err;
         unsigned char data;
         struct usb_device *dev = chip->dev;
+        struct uac_clock_source_descriptor *cs_desc =
+                snd_usb_find_clock_source(chip->ctrl_intf, source_id);
+
+        if (!cs_desc)
+                return 0;
+
+        /* If a clock source can't tell us whether it's valid, we assume it is */
+        if (!uac2_control_is_readable(cs_desc->bmControls, UAC2_CS_CONTROL_CLOCK_VALID))
+                return 1;
 
         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
@@ -114,7 +123,7 @@ static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
         if (err < 0) {
                 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
                            __func__, source_id);
-                return err;
+                return 0;
         }
 
         return !!data;