[PATCH 2/2] ACPI / APEI: clear error status before acknowledging the error

[Manoj Iyer]

From: Tyler Baicar <tbaicar at codeaurora.org>

Currently we acknowledge errors before clearing the error status.
This could cause a new error to be populated by firmware in-between
the error acknowledgment and the error status clearing which would
cause the second error's status to be cleared without being handled.
So, clear the error status before acknowledging the errors.

Also, make sure to acknowledge the error if the error status read
fails.

BugLink: https://launchpad.net/bugs/1732990

Signed-off-by: Tyler Baicar <tbaicar at codeaurora.org>
Reviewed-by: Borislav Petkov <bp at suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
(cherry picked from commit aaf2c2fb0f51f91c699039440862b6ae9c25c10e)
Signed-off-by: Manoj Iyer <manoj.iyer at canonical.com>
---
 drivers/acpi/apei/ghes.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index d661d452b238..8d43b1cecfbe 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -743,17 +743,19 @@ static int ghes_proc(struct ghes *ghes)
 	}
 	ghes_do_proc(ghes, ghes->estatus);
 
+out:
+	ghes_clear_estatus(ghes);
+
+	if (rc == -ENOENT)
+		return rc;
+
 	/*
 	 * GHESv2 type HEST entries introduce support for error acknowledgment,
 	 * so only acknowledge the error if this support is present.
 	 */
-	if (is_hest_type_generic_v2(ghes)) {
-		rc = ghes_ack_error(ghes->generic_v2);
-		if (rc)
-			return rc;
-	}
-out:
-	ghes_clear_estatus(ghes);
+	if (is_hest_type_generic_v2(ghes))
+		return ghes_ack_error(ghes->generic_v2);
+
 	return rc;
 }
 
-- 
2.14.1