ALSA: usb-audio: Fix invalid NULL check in snd_emuusb_set_samplerate()

commit 6de3c9e3f6b3eaf66859e1379b3f35dda781416b upstream.

The quirk function snd_emuusb_set_samplerate() has a NULL check for
the mixer element, but this is useless in the current code.  It used
to be a check against mixer->id_elems[unitid] but it was changed later
to the value after mixer_eleme_list_to_info() which is always non-NULL
due to the container_of() usage.

This patch fixes the check before the conversion.

While we're at it, correct a typo in the comment in the function,
too.

Fixes: 8c558076c740 ("ALSA: usb-audio: Clean up mixer element list traverse")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
index 199fa157a411e4731fa56e477f0953b2c8fd68ea..27dcb3743690f7c29764fb978823f0f37ad9c977 100644 (file)
--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -1155,17 +1155,17 @@ void snd_emuusb_set_samplerate(struct snd_usb_audio *chip,
 {
        struct usb_mixer_interface *mixer;
        struct usb_mixer_elem_info *cval;
-       int unitid = 12; /* SamleRate ExtensionUnit ID */
+       int unitid = 12; /* SampleRate ExtensionUnit ID */
 
        list_for_each_entry(mixer, &chip->mixer_list, list) {
-               cval = mixer_elem_list_to_info(mixer->id_elems[unitid]);
-               if (cval) {
+               if (mixer->id_elems[unitid]) {
+                       cval = mixer_elem_list_to_info(mixer->id_elems[unitid]);
                        snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR,
                                                    cval->control << 8,
                                                    samplerate_id);
                        snd_usb_mixer_notify_id(mixer, unitid);
+                       break;
                }
-               break;
        }
 }