Commit 928b0fe7 authored by Martin Bugge's avatar Martin Bugge Committed by Mauro Carvalho Chehab
Browse files

[media] adv7511: verify EDID header 



Ignore EDID's where the header is wrong.

Signed-off-by: default avatarMartin Bugge <marbugge@cisco.com>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 3ecabed1

drivers/media/i2c/adv7511.c

+24 −11
Original line number Diff line number Diff line
@@ -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 (!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;

}

	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 adv7511_state *state = get_adv7511_state(sd);

	u8 *data = state->edid.data;



	if (segment != 0)

		return true;

	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);