[PATCH] dmi: Make dmi_walk and dmi_walk_early return real error codes

[Darren Hart <dvhart@infradead.org>]

From: Andy Lutomirski <luto@kernel.org>

Currently they return -1 on error, which will confuse callers if
they try to interpret it as a normal negative error code.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Jean Delvare <jdelvare@suse.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
---
 drivers/firmware/dmi_scan.c | 9 +++++----
 include/linux/dmi.h         | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 54be60e..08b3c8b 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -144,7 +144,7 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
 
 	buf = dmi_early_remap(dmi_base, orig_dmi_len);
 	if (buf == NULL)
-		return -1;
+		return -ENOMEM;
 
 	dmi_decode_table(buf, decode, NULL);
 
@@ -992,7 +992,8 @@ EXPORT_SYMBOL(dmi_get_date);
  *	@decode: Callback function
  *	@private_data: Private data to be passed to the callback function
  *
- *	Returns -1 when the DMI table can't be reached, 0 on success.
+ *	Returns 0 on success, -ENXIO if DMI is not selected or not present,
+ *	or a different negative error code if DMI walking fails.
  */
 int dmi_walk(void (*decode)(const struct dmi_header *, void *),
 	     void *private_data)
@@ -1000,11 +1001,11 @@ int dmi_walk(void (*decode)(const struct dmi_header *, void *),
 	u8 *buf;
 
 	if (!dmi_available)
-		return -1;
+		return -ENOENT;
 
 	buf = dmi_remap(dmi_base, dmi_len);
 	if (buf == NULL)
-		return -1;
+		return -ENOMEM;
 
 	dmi_decode_table(buf, decode, private_data);
 
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index 5e9c74c..9bbf21a 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -136,7 +136,7 @@ static inline int dmi_name_in_vendors(const char *s) { return 0; }
 static inline int dmi_name_in_serial(const char *s) { return 0; }
 #define dmi_available 0
 static inline int dmi_walk(void (*decode)(const struct dmi_header *, void *),
-	void *private_data) { return -1; }
+	void *private_data) { return -ENXIO; }
 static inline bool dmi_match(enum dmi_field f, const char *str)
 	{ return false; }
 static inline void dmi_memdev_name(u16 handle, const char **bank,
-- 
2.9.4