From 4c8d49bc476c7cf1fb7377b469ced43ced470027 Mon Sep 17 00:00:00 2001
From: Richard Fitzgerald <rf@opensource.cirrus.com>
Date: Fri, 15 Oct 2021 14:36:18 +0100
Subject: [PATCH] ASoC: cs42l42: Fix WARN in remove() if running without an interrupt
Git-commit: 4c8d49bc476c7cf1fb7377b469ced43ced470027
Patch-mainline: v5.16-rc1
References: bsc#1203699

The driver must free the IRQ in remove() to prevent the potential race
where an IRQ starts to be handled while the driver is being removed but
devres has not yet called free_irq(). However, the driver can run without
an interrupt but devm_free_irq() will hit a WARN() if no devres-managed
interrupt was ever created.

Fix this by only attempting to create the interrupt handler if the hardware
config specified an interrupt, and failing probe() if the interrupt could
not be created. This means that in cs42l42_remove() an interrupt must have
been registered if the irq number is valid and therefore it is safe to call
devm_free_irq().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20211015133619.4698-16-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 sound/soc/codecs/cs42l42.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 390cd7ea3a7f..c6d91ad996e0 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -1975,17 +1975,21 @@ static int cs42l42_i2c_probe(struct i2c_client *i2c_client,
 	}
 	usleep_range(CS42L42_BOOT_TIME_US, CS42L42_BOOT_TIME_US * 2);
 
-	/* Request IRQ */
-	ret = devm_request_threaded_irq(&i2c_client->dev,
-			i2c_client->irq,
-			NULL, cs42l42_irq_thread,
-			IRQF_ONESHOT | IRQF_TRIGGER_LOW,
-			"cs42l42", cs42l42);
-	if (ret == -EPROBE_DEFER)
-		goto err_disable;
-	else if (ret != 0)
-		dev_err(&i2c_client->dev,
-			"Failed to request IRQ: %d\n", ret);
+	/* Request IRQ if one was specified */
+	if (i2c_client->irq) {
+		ret = devm_request_threaded_irq(&i2c_client->dev,
+						i2c_client->irq,
+						NULL, cs42l42_irq_thread,
+						IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+						"cs42l42", cs42l42);
+		if (ret == -EPROBE_DEFER) {
+			goto err_disable;
+		} else if (ret != 0) {
+			dev_err(&i2c_client->dev,
+				"Failed to request IRQ: %d\n", ret);
+			goto err_disable;
+		}
+	}
 
 	/* initialize codec */
 	devid = cirrus_read_device_id(cs42l42->regmap, CS42L42_DEVID_AB);
@@ -2056,7 +2060,9 @@ static int cs42l42_i2c_remove(struct i2c_client *i2c_client)
 {
 	struct cs42l42_private *cs42l42 = i2c_get_clientdata(i2c_client);
 
-	devm_free_irq(&i2c_client->dev, i2c_client->irq, cs42l42);
+	if (i2c_client->irq)
+		devm_free_irq(&i2c_client->dev, i2c_client->irq, cs42l42);
+
 	pm_runtime_suspend(&i2c_client->dev);
 	pm_runtime_disable(&i2c_client->dev);
 
-- 
2.35.3