ALSA: line6: Fix POD sysfs attributes segfault

commit b027d11263836a0cd335520175257dcb99b43757 upstream.

The commit 02fc76f6a changed base of the sysfs attributes from device to card.
The "show" callbacks dereferenced wrong objects because of this.

Fixes: 02fc76f6a7db ('ALSA: line6: Create sysfs via snd_card_add_dev_attr()')
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Andrej Krutak <dev@andree.sk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/usb/line6/pod.c b/sound/usb/line6/pod.c
index daf81d169a42043f265a48df58afcc5490d40f97..45dd34874f43a7f00fc481b25d7b5bf80ffb6c02 100644 (file)
--- a/sound/usb/line6/pod.c
+++ b/sound/usb/line6/pod.c
@@ -244,8 +244,8 @@ static int pod_set_system_param_int(struct usb_line6_pod *pod, int value,
 static ssize_t serial_number_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
 {
-       struct usb_interface *interface = to_usb_interface(dev);
-       struct usb_line6_pod *pod = usb_get_intfdata(interface);
+       struct snd_card *card = dev_to_snd_card(dev);
+       struct usb_line6_pod *pod = card->private_data;
 
        return sprintf(buf, "%u\n", pod->serial_number);
 }
@@ -256,8 +256,8 @@ static ssize_t serial_number_show(struct device *dev,
 static ssize_t firmware_version_show(struct device *dev,
                                     struct device_attribute *attr, char *buf)
 {
-       struct usb_interface *interface = to_usb_interface(dev);
-       struct usb_line6_pod *pod = usb_get_intfdata(interface);
+       struct snd_card *card = dev_to_snd_card(dev);
+       struct usb_line6_pod *pod = card->private_data;
 
        return sprintf(buf, "%d.%02d\n", pod->firmware_version / 100,
                       pod->firmware_version % 100);
@@ -269,8 +269,8 @@ static ssize_t firmware_version_show(struct device *dev,
 static ssize_t device_id_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
 {
-       struct usb_interface *interface = to_usb_interface(dev);
-       struct usb_line6_pod *pod = usb_get_intfdata(interface);
+       struct snd_card *card = dev_to_snd_card(dev);
+       struct usb_line6_pod *pod = card->private_data;
 
        return sprintf(buf, "%d\n", pod->device_id);
 }