[PATCH] firmware: arm_sdei: Make sdei_unregister_ghes() return void

[Uwe Kleine-König]

Unregistering a ghes shouldn't fail (because how can firmware refuse to
disable an event on unregister). And the callers are not really in a
position to handle errors. (Note: The return value of platform remove
callbacks is ignored.) So make sdei_unregister_ghes() return void and
add warnings at the few locations that can theoretically fail.

!IS_ENABLED(CONFIG_ACPI_APEI_GHES) and
!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE) cannot be hit here, because if
these aren't given, ghex_probe() already fails and so ghes_remove()
isn't called.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
Hello,

this is a follow up on https://lore.kernel.org/linux-acpi/CAJZ5v0ifb-wvyp0JRq_4c1L6vTi_qEeXJ6P=Pmmq_56xRL74_A@mail.gmail.com

Best regards
Uwe

 drivers/acpi/apei/ghes.c    | 12 +++---------
 drivers/firmware/arm_sdei.c | 14 +++++++-------
 include/linux/arm_sdei.h    |  2 +-
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 066dc1f5c235..a593998f2e1e 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -1275,12 +1275,9 @@ static int apei_sdei_register_ghes(struct ghes *ghes)
 				 ghes_sdei_critical_callback);
 }
 
-static int apei_sdei_unregister_ghes(struct ghes *ghes)
+static void apei_sdei_unregister_ghes(struct ghes *ghes)
 {
-	if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE))
-		return -EOPNOTSUPP;
-
-	return sdei_unregister_ghes(ghes);
+	sdei_unregister_ghes(ghes);
 }
 
 static int ghes_probe(struct platform_device *ghes_dev)
@@ -1421,7 +1418,6 @@ static int ghes_probe(struct platform_device *ghes_dev)
 
 static int ghes_remove(struct platform_device *ghes_dev)
 {
-	int rc;
 	struct ghes *ghes;
 	struct acpi_hest_generic *generic;
 
@@ -1455,9 +1451,7 @@ static int ghes_remove(struct platform_device *ghes_dev)
 		ghes_nmi_remove(ghes);
 		break;
 	case ACPI_HEST_NOTIFY_SOFTWARE_DELEGATED:
-		rc = apei_sdei_unregister_ghes(ghes);
-		if (rc)
-			return rc;
+		apei_sdei_unregister_ghes(ghes);
 		break;
 	default:
 		BUG();
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index 1e1a51510e83..7af619464183 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -889,7 +889,7 @@ int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
 	return err;
 }
 
-int sdei_unregister_ghes(struct ghes *ghes)
+void sdei_unregister_ghes(struct ghes *ghes)
 {
 	int i;
 	int err;
@@ -897,16 +897,15 @@ int sdei_unregister_ghes(struct ghes *ghes)
 
 	might_sleep();
 
-	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
-		return -EOPNOTSUPP;
-
 	/*
 	 * The event may be running on another CPU. Disable it
 	 * to stop new events, then try to unregister a few times.
 	 */
 	err = sdei_event_disable(event_num);
-	if (err)
-		return err;
+	if (err) {
+		dev_warn(ghes->dev, "Failed to disable event %u: %pe\n", event_num, ERR_PTR(err));
+		return;
+	}
 
 	for (i = 0; i < 3; i++) {
 		err = sdei_event_unregister(event_num);
@@ -916,7 +915,8 @@ int sdei_unregister_ghes(struct ghes *ghes)
 		schedule();
 	}
 
-	return err;
+	if (err)
+		dev_warn(ghes->dev, "Failed to disable event %u: %pe\n", event_num, ERR_PTR(err));
 }
 
 static int sdei_get_conduit(struct platform_device *pdev)
diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
index 14dc461b0e82..0812af4530a4 100644
--- a/include/linux/arm_sdei.h
+++ b/include/linux/arm_sdei.h
@@ -40,7 +40,7 @@ int sdei_event_disable(u32 event_num);
 /* GHES register/unregister helpers */
 int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
 		       sdei_event_callback *critical_cb);
-int sdei_unregister_ghes(struct ghes *ghes);
+void sdei_unregister_ghes(struct ghes *ghes);
 
 #ifdef CONFIG_ARM_SDE_INTERFACE
 /* For use by arch code when CPU hotplug notifiers are not appropriate. */

base-commit: aeba12b26c79fc35e07e511f692a8907037d95da
-- 
2.38.1