1 files changed, 45 insertions, 26 deletions

diff --git a/sound/soc/codecs/rt5677.c b/sound/soc/codecs/rt5677.c
index b5ae61ff87af..202af7135f07 100644
--- a/sound/soc/codecs/rt5677.c
+++ b/sound/soc/codecs/rt5677.c
@@ -5072,38 +5072,57 @@ static const struct rt5677_irq_desc rt5677_irq_descs[] = {
 static irqreturn_t rt5677_irq(int unused, void *data)
 {
 	struct rt5677_priv *rt5677 = data;
-	int ret = 0, i, reg_irq, virq;
+	int ret = 0, loop, i, reg_irq, virq;
 	bool irq_fired = false;
 
 	mutex_lock(&rt5677->irq_lock);
-	/* Read interrupt status */
-	ret = regmap_read(rt5677->regmap, RT5677_IRQ_CTRL1, &reg_irq);
-	if (ret) {
-		dev_err(rt5677->dev, "failed reading IRQ status: %d\n", ret);
-		goto exit;
-	}
 
-	for (i = 0; i < RT5677_IRQ_NUM; i++) {
-		if (reg_irq & rt5677_irq_descs[i].status_mask) {
-			irq_fired = true;
-			virq = irq_find_mapping(rt5677->domain, i);
-			if (virq)
-				handle_nested_irq(virq);
-
-			/* Clear the interrupt by flipping the polarity of the
-			 * interrupt source line that fired
-			 */
-			reg_irq ^= rt5677_irq_descs[i].polarity_mask;
+	/*
+	 * Loop to handle interrupts until the last i2c read shows no pending
+	 * irqs. The interrupt line is shared by multiple interrupt sources.
+	 * After the regmap_read() below, a new interrupt source line may
+	 * become high before the regmap_write() finishes, so there isn't a
+	 * rising edge on the shared interrupt line for the new interrupt. Thus,
+	 * the loop is needed to avoid missing irqs.
+	 *
+	 * A safeguard of 20 loops is used to avoid hanging in the irq handler
+	 * if there is something wrong with the interrupt status update. The
+	 * interrupt sources here are audio jack plug/unplug events which
+	 * shouldn't happen at a high frequency for a long period of time.
+	 * Empirically, more than 3 loops have never been seen.
+	 */
+	for (loop = 0; loop < 20; loop++) {
+		/* Read interrupt status */
+		ret = regmap_read(rt5677->regmap, RT5677_IRQ_CTRL1, &reg_irq);
+		if (ret) {
+			dev_err(rt5677->dev, "failed reading IRQ status: %d\n",
+				ret);
+			goto exit;
 		}
-	}
 
-	if (!irq_fired)
-		goto exit;
-
-	ret = regmap_write(rt5677->regmap, RT5677_IRQ_CTRL1, reg_irq);
-	if (ret) {
-		dev_err(rt5677->dev, "failed updating IRQ status: %d\n", ret);
-		goto exit;
+		irq_fired = false;
+		for (i = 0; i < RT5677_IRQ_NUM; i++) {
+			if (reg_irq & rt5677_irq_descs[i].status_mask) {
+				irq_fired = true;
+				virq = irq_find_mapping(rt5677->domain, i);
+				if (virq)
+					handle_nested_irq(virq);
+
+				/* Clear the interrupt by flipping the polarity
+				 * of the interrupt source line that fired
+				 */
+				reg_irq ^= rt5677_irq_descs[i].polarity_mask;
+			}
+		}
+		if (!irq_fired)
+			goto exit;
+
+		ret = regmap_write(rt5677->regmap, RT5677_IRQ_CTRL1, reg_irq);
+		if (ret) {
+			dev_err(rt5677->dev, "failed updating IRQ status: %d\n",
+				ret);
+			goto exit;
+		}
 	}
 exit:
 	mutex_unlock(&rt5677->irq_lock);