From: Haotian Zhang <vulab@iscas.ac.cn>
Date: Mon, 15 Dec 2025 02:01:14 +0000 (+0800)
Subject: counter: 104-quad-8: Fix incorrect return value in IRQ handler
X-Git-Tag: v6.19-rc5~2^2~2^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9517d76dd160208b7a432301ce7bec8fc1ddc305;p=thirdparty%2Fkernel%2Flinux.git

counter: 104-quad-8: Fix incorrect return value in IRQ handler

quad8_irq_handler() should return irqreturn_t enum values, but it
directly returns negative errno codes from regmap operations on error.

Return IRQ_NONE if the interrupt status cannot be read. If clearing the
interrupt fails, return IRQ_HANDLED to prevent the kernel from disabling
the IRQ line due to a spurious interrupt storm. Also, log these regmap
failures with dev_WARN_ONCE.

Fixes: 98ffe0252911 ("counter: 104-quad-8: Migrate to the regmap API")
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20251215020114.1913-1-vulab@iscas.ac.cn
Cc: stable@vger.kernel.org
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
---

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index ce81fc4e1ae7..573b2fe93253 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -1192,6 +1192,7 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
 {
 	struct counter_device *counter = private;
 	struct quad8 *const priv = counter_priv(counter);
+	struct device *dev = counter->parent;
 	unsigned int status;
 	unsigned long irq_status;
 	unsigned long channel;
@@ -1200,8 +1201,11 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
 	int ret;
 
 	ret = regmap_read(priv->map, QUAD8_INTERRUPT_STATUS, &status);
-	if (ret)
-		return ret;
+	if (ret) {
+		dev_WARN_ONCE(dev, true,
+			"Attempt to read Interrupt Status Register failed: %d\n", ret);
+		return IRQ_NONE;
+	}
 	if (!status)
 		return IRQ_NONE;
 
@@ -1223,8 +1227,9 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
 				break;
 		default:
 			/* should never reach this path */
-			WARN_ONCE(true, "invalid interrupt trigger function %u configured for channel %lu\n",
-				  flg_pins, channel);
+			dev_WARN_ONCE(dev, true,
+				"invalid interrupt trigger function %u configured for channel %lu\n",
+				flg_pins, channel);
 			continue;
 		}
 
@@ -1232,8 +1237,11 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
 	}
 
 	ret = regmap_write(priv->map, QUAD8_CHANNEL_OPERATION, CLEAR_PENDING_INTERRUPTS);
-	if (ret)
-		return ret;
+	if (ret) {
+		dev_WARN_ONCE(dev, true,
+			"Attempt to clear pending interrupts by writing to Channel Operation Register failed: %d\n", ret);
+		return IRQ_HANDLED;
+	}
 
 	return IRQ_HANDLED;
 }