From: Adrian Huang <adrian.huang@hp.com>
Date: Fri, 14 Dec 2012 23:30:07 +0000 (+0100)
Subject: ACPI / APEI: Fix the returned value in erst_dbg_read
X-Git-Tag: firefly_0821_release~3680^2~1296^2~4^2~5
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6780aa683d4d83ed887dd07b7987947d339d76f1;p=firefly-linux-kernel-4.4.55.git

ACPI / APEI: Fix the returned value in erst_dbg_read

If the persistent store is empty initially, the function 'erst_dbg_read'
returns a nonzero value. The better way is to return a zero indicating the
read operation reaches EOF.

Tested on two different servers.

Signed-off-by: Adrian Huang <adrian.huang@hp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

diff --git a/drivers/acpi/apei/erst-dbg.c b/drivers/acpi/apei/erst-dbg.c
index 903549df809b..04ab5c9d3ced 100644
--- a/drivers/acpi/apei/erst-dbg.c
+++ b/drivers/acpi/apei/erst-dbg.c
@@ -111,8 +111,17 @@ retry_next:
 	if (rc)
 		goto out;
 	/* no more record */
-	if (id == APEI_ERST_INVALID_RECORD_ID)
+	if (id == APEI_ERST_INVALID_RECORD_ID) {
+		/*
+		 * If the persistent store is empty initially, the function
+		 * 'erst_read' below will return "-ENOENT" value. This causes
+		 * 'retry_next' label is entered again. The returned value
+		 * should be zero indicating the read operation is EOF.
+		 */
+		len = 0;
+
 		goto out;
+	}
 retry:
 	rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len);
 	/* The record may be cleared by others, try read next record */