1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/media/i2c/adv7511.c b/drivers/media/i2c/adv7511.c
index f20450c8156f..ee618942cb8e 100644
--- a/drivers/media/i2c/adv7511.c
+++ b/drivers/media/i2c/adv7511.c
@@ -965,26 +965,38 @@ static void adv7511_check_monitor_present_status(struct v4l2_subdev *sd)
 
 static bool edid_block_verify_crc(uint8_t *edid_block)
 {
-        int i;
         uint8_t sum = 0;
+        int i;
 
         for (i = 0; i < 128; i++)
-                sum += *(edid_block + i);
-        return (sum == 0);
+                sum += edid_block[i];
+        return sum == 0;
 }
 
-static bool edid_segment_verify_crc(struct v4l2_subdev *sd, u32 segment)
+static bool edid_verify_crc(struct v4l2_subdev *sd, u32 segment)
 {
         struct adv7511_state *state = get_adv7511_state(sd);
         u32 blocks = state->edid.blocks;
         uint8_t *data = state->edid.data;
 
-        if (edid_block_verify_crc(&data[segment * 256])) {
-                if ((segment + 1) * 2 <= blocks)
-                        return edid_block_verify_crc(&data[segment * 256 + 128]);
+        if (!edid_block_verify_crc(&data[segment * 256]))
+                return false;
+        if ((segment + 1) * 2 <= blocks)
+                return edid_block_verify_crc(&data[segment * 256 + 128]);
+        return true;
+}
+
+static bool edid_verify_header(struct v4l2_subdev *sd, u32 segment)
+{
+        static const u8 hdmi_header[] = {
+                0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
+        };
+        struct adv7511_state *state = get_adv7511_state(sd);
+        u8 *data = state->edid.data;
+
+        if (segment != 0)
                 return true;
-        }
-        return false;
+        return !memcmp(data, hdmi_header, sizeof(hdmi_header));
 }
 
 static bool adv7511_check_edid_status(struct v4l2_subdev *sd)
@@ -1013,9 +1025,10 @@ static bool adv7511_check_edid_status(struct v4l2_subdev *sd)
                         state->edid.blocks = state->edid.data[0x7e] + 1;
                         v4l2_dbg(1, debug, sd, "%s: %d blocks in total\n", __func__, state->edid.blocks);
                 }
-                if (!edid_segment_verify_crc(sd, segment)) {
+                if (!edid_verify_crc(sd, segment) ||
+                    !edid_verify_header(sd, segment)) {
                         /* edid crc error, force reread of edid segment */
-                        v4l2_dbg(1, debug, sd, "%s: edid crc error\n", __func__);
+                        v4l2_err(sd, "%s: edid crc or header error\n", __func__);
                         state->have_monitor = false;
                         adv7511_s_power(sd, false);
                         adv7511_s_power(sd, true);