[PATCH] platform/x86: lenovo: convert mutex_init() users to devm_mutex_init()

[surirajat@gmail.com]

From: Rajat Suri <rajat.suri@dell.com>

Convert the mutex_init() calls in thinkpad_acpi to devm_mutex_init()
so that the mutex lifecycle is managed by devres.

This fixes thinkpad_acpi, which never destroyed the hotkey, brightness,
volume and fan mutexes on its teardown path.

Per feedback, the patch now covers only driver code for hardware validated so far.

Details per driver:

 - thinkpad_acpi: bind the hotkey, hotkey thread data, brightness, volume
   and fan mutexes to tpacpi_pdev, which is registered before any
   subdriver init runs, and propagate a possible failure from
   devm_mutex_init().

No functional change intended.

Signed-off-by: Rajat Suri <rajat.suri@dell.com>
---
 drivers/platform/x86/lenovo/thinkpad_acpi.c | 22 ++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/platform/x86/lenovo/thinkpad_acpi.c b/drivers/platform/x86/lenovo/thinkpad_acpi.c
index 4f81855ad721..0fc105fc28d0 100644
--- a/drivers/platform/x86/lenovo/thinkpad_acpi.c
+++ b/drivers/platform/x86/lenovo/thinkpad_acpi.c
@@ -3381,10 +3381,14 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 	       tpacpi_inputdev->close != NULL);
 
 	TPACPI_ACPIHANDLE_INIT(hkey);
-	mutex_init(&hotkey_mutex);
+	res = devm_mutex_init(&tpacpi_pdev->dev, &hotkey_mutex);
+	if (res)
+		return res;
 
 #ifdef CONFIG_THINKPAD_ACPI_HOTKEY_POLL
-	mutex_init(&hotkey_thread_data_mutex);
+	res = devm_mutex_init(&tpacpi_pdev->dev, &hotkey_thread_data_mutex);
+	if (res)
+		return res;
 #endif
 
 	/* hotkey not supported on 570 */
@@ -6830,11 +6834,14 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 {
 	struct backlight_properties props;
 	int b;
+	int ret;
 	unsigned long quirks;
 
 	vdbg_printk(TPACPI_DBG_INIT, "initializing brightness subdriver\n");
 
-	mutex_init(&brightness_mutex);
+	ret = devm_mutex_init(&tpacpi_pdev->dev, &brightness_mutex);
+	if (ret)
+		return ret;
 
 	quirks = tpacpi_check_quirks(brightness_quirk_table,
 				ARRAY_SIZE(brightness_quirk_table));
@@ -7575,7 +7582,9 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 
 	vdbg_printk(TPACPI_DBG_INIT, "initializing volume subdriver\n");
 
-	mutex_init(&volume_mutex);
+	rc = devm_mutex_init(&tpacpi_pdev->dev, &volume_mutex);
+	if (rc)
+		return rc;
 
 	/*
 	 * Check for module parameter bogosity, note that we
@@ -8913,11 +8922,14 @@ static const struct tpacpi_quirk fan_quirk_table[] __initconst = {
 static int __init fan_init(struct ibm_init_struct *iibm)
 {
 	unsigned long quirks;
+	int ret;
 
 	vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_FAN,
 			"initializing fan subdriver\n");
 
-	mutex_init(&fan_mutex);
+	ret = devm_mutex_init(&tpacpi_pdev->dev, &fan_mutex);
+	if (ret)
+		return ret;
 	fan_status_access_mode = TPACPI_FAN_NONE;
 	fan_control_access_mode = TPACPI_FAN_WR_NONE;
 	fan_control_commands = 0;
-- 
2.43.0