[PATCH v3 2/5] platform/x86: panasonic-laptop: Fix OPTD notifier registration and cleanup

[Rafael J. Wysocki]

From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>

An ACPI notify handler is leaked if device_create_file() returns an
error in acpi_pcc_hotkey_add().

Also, it is pointless to call pcc_unregister_optd_notifier() in
acpi_pcc_hotkey_remove() if pcc->platform is NULL and it is better
to arrange the cleanup code in that function in the same order as
the rollback code in acpi_pcc_hotkey_add().

Address the above by placing the pcc_register_optd_notifier() call in
acpi_pcc_hotkey_add() after the device_create_file() return value
check and placing the pcc_unregister_optd_notifier() call in
acpi_pcc_hotkey_remove() right before the device_remove_file() call.

Fixes: d5a81d8e864b ("platform/x86: panasonic-laptop: Add support for optical driver power in Y and W series")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---

v2 -> v3: Do not fail probing on OPTD registration errors (note that it is
   not a bug to attempt to unregister an ACPI notify handler that has not
   been registered)

v1 -> v2: New patch

---
 drivers/platform/x86/panasonic-laptop.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
index a481f2602ce3..56b4e61d7e5c 100644
--- a/drivers/platform/x86/panasonic-laptop.c
+++ b/drivers/platform/x86/panasonic-laptop.c
@@ -1090,9 +1090,10 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device)
 		}
 		result = device_create_file(&pcc->platform->dev,
 			&dev_attr_cdpower);
-		pcc_register_optd_notifier(pcc, "\\_SB.PCI0.EHCI.ERHB.OPTD");
 		if (result)
 			goto out_platform;
+
+		pcc_register_optd_notifier(pcc, "\\_SB.PCI0.EHCI.ERHB.OPTD");
 	} else {
 		pcc->platform = NULL;
 	}
@@ -1126,10 +1127,10 @@ static void acpi_pcc_hotkey_remove(struct acpi_device *device)
 	i8042_remove_filter(panasonic_i8042_filter);
 
 	if (pcc->platform) {
+		pcc_unregister_optd_notifier(pcc, "\\_SB.PCI0.EHCI.ERHB.OPTD");
 		device_remove_file(&pcc->platform->dev, &dev_attr_cdpower);
 		platform_device_unregister(pcc->platform);
 	}
-	pcc_unregister_optd_notifier(pcc, "\\_SB.PCI0.EHCI.ERHB.OPTD");
 
 	sysfs_remove_group(&device->dev.kobj, &pcc_attr_group);
 
-- 
2.51.0