[PATCH 1/3] drm/edid: new drm_edid_block_checksum helper function V2

[Stefan Brüns]

The function will also be used by a later patch, so factor it out.

V2: make raw_edid const, define/declare before first use

Signed-off-by: Stefan Brüns <stefan.bruens at rwth-aachen.de>
Reviewed-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/drm_edid.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a71ed93..f6c4a1d 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1022,6 +1022,16 @@ static bool drm_edid_is_zero(const u8 *in_edid, int length)
 	return true;
 }
 
+static u8 drm_edid_block_checksum(const u8 *raw_edid)
+{
+	int i;
+	u8 csum = 0;
+	for (i = 0; i < EDID_LENGTH; i++)
+		csum += raw_edid[i];
+
+	return csum;
+}
+
 /**
  * drm_edid_block_valid - Sanity check the EDID block (base or extension)
  * @raw_edid: pointer to raw EDID block
@@ -1036,7 +1046,6 @@ static bool drm_edid_is_zero(const u8 *in_edid, int length)
 bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
 {
 	int i;
-	u8 csum = 0;
 	struct edid *edid = (struct edid *)raw_edid;
 
 	if (WARN_ON(!raw_edid))
@@ -1056,9 +1065,7 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
 		}
 	}
 
-	for (i = 0; i < EDID_LENGTH; i++)
-		csum += raw_edid[i];
-	if (csum) {
+	if (drm_edid_block_checksum(raw_edid)) {
 		if (print_bad_edid) {
 			DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
 		}
-- 
2.1.2