MLK-11933 mfd: mxc-hdmi-core: null check substream before using it

null check substream before using it. Reported by coverity.

Signed-off-by: Zidan Wang <zidan.wang@freescale.com>
(cherry picked from commit fad2b9c1285a34eab0dec9f90edc06ec94e70a61)

diff --git a/drivers/mfd/mxc-hdmi-core.c b/drivers/mfd/mxc-hdmi-core.c
index ca79e7e..a670406 100644 (file)
--- a/drivers/mfd/mxc-hdmi-core.c
+++ b/drivers/mfd/mxc-hdmi-core.c
@@ -153,9 +153,12 @@ int mxc_hdmi_register_audio(struct snd_pcm_substream *substream)
        unsigned long flags, flags1;
        int ret = 0;
 
+       if (!substream)
+               return -EINVAL;
+
        snd_pcm_stream_lock_irqsave(substream, flags);
 
-       if (substream && check_hdmi_state()) {
+       if (check_hdmi_state()) {
                spin_lock_irqsave(&hdmi_audio_lock, flags1);
                if (hdmi_audio_stream_playback) {
                        pr_err("%s unconsist hdmi auido stream!\n", __func__);