[PATCH v2 1/2] hwmon: (lenovo-ec-sensors): Convert to devm_request_region()

[Kean Ren]

Replace manual request_region()/release_region() with
devm_request_region().  This lets the device-managed framework
handle I/O region lifetime automatically and fixes:

- A double release_region() when probe fails after acquiring the
  I/O region: the probe error path releases it, and then
  lenovo_ec_init() releases it again on the same error path.

- A release-after-use window in lenovo_ec_exit() where
  release_region() was called before platform_device_unregister(),
  leaving the hwmon device active with a released I/O region.

- Missing release_region() in lenovo_ec_probe() if
  devm_hwmon_device_register_with_info() fails.

Remove all five manual release_region() calls that are now handled
automatically, and drop the unnecessary braces on the single-statement
blocks that previously contained them.

Reviewed-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
Signed-off-by: Kean Ren <rh_king@xxxxxxx>
---
Changes in v2: Removed unnecessary error messages

 drivers/hwmon/lenovo-ec-sensors.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/lenovo-ec-sensors.c b/drivers/hwmon/lenovo-ec-sensors.c
index 8681bbf6665b..45db49e189d3 100644
--- a/drivers/hwmon/lenovo-ec-sensors.c
+++ b/drivers/hwmon/lenovo-ec-sensors.c
@@ -519,8 +519,8 @@ static int lenovo_ec_probe(struct platform_device *pdev)
 	if (!ec_data)
 		return -ENOMEM;
 
-	if (!request_region(IO_REGION_START, IO_REGION_LENGTH, "LNV-WKS")) {
-		pr_err(":request fail\n");
+	if (!devm_request_region(dev, IO_REGION_START, IO_REGION_LENGTH, "LNV-WKS")) {
+		dev_err(dev, "Failed to request I/O region\n");
 		return -EIO;
 	}
 
@@ -541,7 +541,6 @@ static int lenovo_ec_probe(struct platform_device *pdev)
 	    (inb_p(MCHP_EMI0_EC_DATA_BYTE1) != 'C') &&
 	    (inb_p(MCHP_EMI0_EC_DATA_BYTE2) != 'H') &&
 	    (inb_p(MCHP_EMI0_EC_DATA_BYTE3) != 'P')) {
-		release_region(IO_REGION_START, IO_REGION_LENGTH);
 		return -ENODEV;
 	}
 
@@ -577,7 +576,6 @@ static int lenovo_ec_probe(struct platform_device *pdev)
 		lenovo_ec_chip_info.info = lenovo_ec_hwmon_info_p8;
 		break;
 	default:
-		release_region(IO_REGION_START, IO_REGION_LENGTH);
 		return -ENODEV;
 	}
 
@@ -607,7 +605,6 @@ static int __init lenovo_ec_init(void)
 				       lenovo_ec_probe, NULL, 0, NULL, 0);
 
 	if (IS_ERR(lenovo_ec_sensors_platform_device)) {
-		release_region(IO_REGION_START, IO_REGION_LENGTH);
 		return PTR_ERR(lenovo_ec_sensors_platform_device);
 	}
 
@@ -617,7 +614,6 @@ module_init(lenovo_ec_init);
 
 static void __exit lenovo_ec_exit(void)
 {
-	release_region(IO_REGION_START, IO_REGION_LENGTH);
 	platform_device_unregister(lenovo_ec_sensors_platform_device);
 	platform_driver_unregister(&lenovo_ec_sensors_platform_driver);
 }
-- 
2.53.0