[media] ad9389b: verify EDID header
Ignore EDIDs where the header is wrong.
Signed-off-by: Mats Randgaard <matrandg@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/i2c/ad9389b.c b/drivers/media/i2c/ad9389b.c
index b06a7e5..e7f7171 100644
--- a/drivers/media/i2c/ad9389b.c
+++ b/drivers/media/i2c/ad9389b.c
@@ -978,7 +978,7 @@
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 ad9389b_state *state = get_ad9389b_state(sd);
u32 blocks = state->edid.blocks;
@@ -992,6 +992,25 @@
return false;
}
+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 ad9389b_state *state = get_ad9389b_state(sd);
+ u8 *data = state->edid.data;
+ int i;
+
+ if (segment)
+ return true;
+
+ for (i = 0; i < ARRAY_SIZE(hdmi_header); i++)
+ if (data[i] != hdmi_header[i])
+ return false;
+
+ return true;
+}
+
static bool ad9389b_check_edid_status(struct v4l2_subdev *sd)
{
struct ad9389b_state *state = get_ad9389b_state(sd);
@@ -1019,9 +1038,10 @@
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_err(sd, "%s: edid crc error\n", __func__);
+ v4l2_err(sd, "%s: edid crc or header error\n", __func__);
state->have_monitor = false;
ad9389b_s_power(sd, false);
ad9389b_s_power(sd, true);