The TD1997x chip retains vper, hper and hsper register values when the
HDMI source is disconnected. Use a different means of checking if the
link is still valid.

Signed-off-by: Krzysztof Hałasa <khalasa@piap.pl>

diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c
index 0b516a45a135..36a7b89afb08 100644
--- a/drivers/media/i2c/tda1997x.c
+++ b/drivers/media/i2c/tda1997x.c

@@ -1107,7 +1107,8 @@ tda1997x_detect_std(struct tda1997x_state *state,
        hper = io_read16(sd, REG_H_PER) & MASK_HPER;
        hsper = io_read16(sd, REG_HS_WIDTH) & MASK_HSWIDTH;
        v4l2_dbg(1, debug, sd, "Signal Timings: %u/%u/%u\n", vper, hper, hsper);
-       if (!vper || !hper || !hsper)
+
+       if (!state->input_detect[0] && !state->input_detect[1])
                return -ENOLINK;

        for (i = 0; v4l2_dv_timings_presets[i].bt.width; i++) {