On real devices, signal strength is always a negative number when represented in dBm. A more interesting range is to use dBmV (which is what Kaffeine does, for example). The conversion from the two units are simple: dBmV = dBm - 108 Usually, signal strength ranges up to 100dBmV. Adjust the maximum value to be around 74 dBmV, when there's no frequency shift, which represents a good signal. With that, Kaffeine displays it a lot better. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> --- drivers/media/test-drivers/vidtv/vidtv_demod.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.c b/drivers/media/test-drivers/vidtv/vidtv_demod.c index c54c88cac84f..c825842758f0 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_demod.c +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c @@ -181,12 +181,18 @@ static void vidtv_demod_update_stats(struct dvb_frontend *fe) c->block_count.stat[0].scale = scale; /* - * Add a 0.5% of randomness at the signal streangth and CNR, + * Add a 0.5% of randomness at the signal strength and CNR, * and make them different, as we want to have something closer * to a real case scenario. + * + * Also, usually, signal strength is a negative number in dBm. */ - c->strength.stat[0].svalue = state->tuner_cnr + prandom_u32_max(state->tuner_cnr / 50); - c->cnr.stat[0].svalue = state->tuner_cnr - prandom_u32_max(state->tuner_cnr / 50); + c->strength.stat[0].svalue = state->tuner_cnr; + c->strength.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50); + c->strength.stat[0].svalue -= 68000; /* Adjust to a better range */ + + c->cnr.stat[0].svalue = state->tuner_cnr; + c->cnr.stat[0].svalue -= prandom_u32_max(state->tuner_cnr / 50); } -- 2.26.2
