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path: root/drivers/acpi/apei/erst-dbg.c
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Diffstat (limited to 'drivers/acpi/apei/erst-dbg.c')
-rw-r--r--drivers/acpi/apei/erst-dbg.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/acpi/apei/erst-dbg.c b/drivers/acpi/apei/erst-dbg.c
index a4cfb64c86a..04ab5c9d3ce 100644
--- a/drivers/acpi/apei/erst-dbg.c
+++ b/drivers/acpi/apei/erst-dbg.c
@@ -33,7 +33,7 @@
#define ERST_DBG_PFX "ERST DBG: "
-#define ERST_DBG_RECORD_LEN_MAX 4096
+#define ERST_DBG_RECORD_LEN_MAX 0x4000
static void *erst_dbg_buf;
static unsigned int erst_dbg_buf_len;
@@ -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 */
@@ -213,6 +222,10 @@ static struct miscdevice erst_dbg_dev = {
static __init int erst_dbg_init(void)
{
+ if (erst_disable) {
+ pr_info(ERST_DBG_PFX "ERST support is disabled.\n");
+ return -ENODEV;
+ }
return misc_register(&erst_dbg_dev);
}