ASoC: Handle spurious wm_hubs DC servo done interrupts

Don't assume the first fire indicates that we're done.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm_hubs.c

@@ -66,8 +66,8 @@ static void wait_for_dc_servo(struct snd_soc_codec *codec, unsigned int op)
 	struct wm_hubs_data *hubs = snd_soc_codec_get_drvdata(codec);
 	unsigned int reg;
 	int count = 0;
+	int timeout;
 	unsigned int val;
-	unsigned long timeout;
 
 	val = op | WM8993_DCS_ENA_CHAN_0 | WM8993_DCS_ENA_CHAN_1;
 
@@ -76,21 +76,23 @@ static void wait_for_dc_servo(struct snd_soc_codec *codec, unsigned int op)
 
 	dev_dbg(codec->dev, "Waiting for DC servo...\n");
 
-	if (hubs->dcs_done_irq) {
-		timeout = wait_for_completion_timeout(&hubs->dcs_done,
-						      msecs_to_jiffies(500));
-		if (timeout == 0)
-			dev_warn(codec->dev, "No DC servo interrupt\n");
+	if (hubs->dcs_done_irq)
+		timeout = 4;
+	else
+		timeout = 400;
 
-		reg = snd_soc_read(codec, WM8993_DC_SERVO_0);
-	} else {
-		do {
-			count++;
+	do {
+		count++;
+
+		if (hubs->dcs_done_irq)
+			wait_for_completion_timeout(&hubs->dcs_done,
+						    msecs_to_jiffies(250));
+		else
 			msleep(1);
-			reg = snd_soc_read(codec, WM8993_DC_SERVO_0);
-			dev_dbg(codec->dev, "DC servo: %x\n", reg);
-		} while (reg & op && count < 400);
-	}
+
+		reg = snd_soc_read(codec, WM8993_DC_SERVO_0);
+		dev_dbg(codec->dev, "DC servo: %x\n", reg);
+	} while (reg & op && count < timeout);
 
 	if (reg & op)
 		dev_err(codec->dev, "Timed out waiting for DC Servo %x\n",