[media] adv7511: verify EDID header

Ignore EDID's where the header is wrong.

Signed-off-by: Martin Bugge <marbugge@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
This commit is contained in:
Martin Bugge 2013-12-17 09:17:10 -03:00 committed by Mauro Carvalho Chehab
parent 3ecabed1ec
commit 928b0fe783

View file

@ -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);