Commit bafd5d79 authored by Mats Randgaard's avatar Mats Randgaard Committed by Mauro Carvalho Chehab
Browse files

[media] ad9389b: verify EDID header 



Ignore EDIDs where the header is wrong.

Signed-off-by: default avatarMats Randgaard <matrandg@cisco.com>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent e63fa180

drivers/media/i2c/ad9389b.c

+23 −3
Original line number Diff line number Diff line
@@ -978,7 +978,7 @@ static bool edid_block_verify_crc(u8 *edid_block) 
	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 @@ static bool edid_segment_verify_crc(struct v4l2_subdev *sd, u32 segment) 
	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 @@ static bool ad9389b_check_edid_status(struct v4l2_subdev *sd) 
		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);