From: Tyler Baicar <tbaicar@codeaurora.org>
Date: Mon, 28 Aug 2017 10:53:41 -0600
Subject: ACPI / APEI: clear error status before acknowledging the error
Git-commit: aaf2c2fb0f51f91c699039440862b6ae9c25c10e
Patch-mainline: v4.14-rc3
References: fate#326419

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.

Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.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 077f9bad6f44..3c3a37b8503b 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;
 }
 
-- 
2.19.1