diff options
| -rw-r--r-- | sound/usb/card.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/sound/usb/card.c b/sound/usb/card.c index 758bb8b05..bb07d48e7 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -218,12 +218,25 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif) struct usb_device *dev = chip->dev; struct usb_host_interface *host_iface; struct usb_interface_descriptor *altsd; + struct usb_interface *usb_iface; void *control_header; int i, protocol; int rest_bytes; + usb_iface = usb_ifnum_to_if(dev, ctrlif); + if (!usb_iface) { + snd_printk(KERN_ERR "%d:%u : does not exist\n", + dev->devnum, ctrlif); + return -EINVAL; + } + /* find audiocontrol interface */ - host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0]; + host_iface = &usb_iface->altsetting[0]; + if (!host_iface) { + snd_printk(KERN_ERR "Audio Control interface is not available."); + return -EINVAL; + } + control_header = snd_usb_find_csint_desc(host_iface->extra, host_iface->extralen, NULL, UAC_HEADER); @@ -281,8 +294,7 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif) case UAC_VERSION_2: { struct usb_interface_assoc_descriptor *assoc = - usb_ifnum_to_if(dev, ctrlif)->intf_assoc; - + usb_iface->intf_assoc; if (!assoc) { /* * Firmware writers cannot count to three. So to find |