ASoC: compress: Fix compress device direction check

commit a1068045 upstream.

The detection of direction for compress was only taking into account codec
capabilities and not CPU ones. Fix this by checking the CPU side capabilities
as well
Tested-by: Ashish Panwar <ashish.panwar@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

sound/soc/soc-compress.c

@@ -626,17 +626,34 @@ int soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num)
 	struct snd_pcm *be_pcm;
 	char new_name[64];
 	int ret = 0, direction = 0;
+	int playback = 0, capture = 0;
 
 	/* check client and interface hw capabilities */
 	snprintf(new_name, sizeof(new_name), "%s %s-%d",
 			rtd->dai_link->stream_name, codec_dai->name, num);
 
 	if (codec_dai->driver->playback.channels_min)
+		playback = 1;
+	if (codec_dai->driver->capture.channels_min)
+		capture = 1;
+
+	capture = capture && cpu_dai->driver->capture.channels_min;
+	playback = playback && cpu_dai->driver->playback.channels_min;
+
+	/*
+	 * Compress devices are unidirectional so only one of the directions
+	 * should be set, check for that (xor)
+	 */
+	if (playback + capture != 1) {
+		dev_err(rtd->card->dev, "Invalid direction for compress P %d, C %d\n",
+				playback, capture);
+		return -EINVAL;
+	}
+
+	if(playback)
 		direction = SND_COMPRESS_PLAYBACK;
-	else if (codec_dai->driver->capture.channels_min)
-		direction = SND_COMPRESS_CAPTURE;
 	else
-		return -EINVAL;
+		direction = SND_COMPRESS_CAPTURE;
 
 	compr = kzalloc(sizeof(*compr), GFP_KERNEL);
 	if (compr == NULL) {