diff options
Diffstat (limited to 'drivers/media/dvb-frontends')
| -rw-r--r-- | drivers/media/dvb-frontends/cxd2841er.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/media/dvb-frontends/cxd2841er.c b/drivers/media/dvb-frontends/cxd2841er.c index 2a698711d25b..95d82c4445e2 100644 --- a/drivers/media/dvb-frontends/cxd2841er.c +++ b/drivers/media/dvb-frontends/cxd2841er.c @@ -1768,8 +1768,13 @@ static void cxd2841er_read_signal_strength(struct dvb_frontend *fe) case SYS_DVBC_ANNEX_A: strength = cxd2841er_read_agc_gain_t_t2(priv, p->delivery_system); - p->strength.stat[0].scale = FE_SCALE_RELATIVE; - p->strength.stat[0].uvalue = strength; + p->strength.stat[0].scale = FE_SCALE_DECIBEL; + /* + * Formula was empirically determinated via linear regression, + * using frequencies: 175 MHz, 410 MHz and 800 MHz, and a + * stream modulated with QAM64 + */ + p->strength.stat[0].uvalue = ((s32)strength) * 4045 / 1000 - 85224; break; case SYS_ISDBT: strength = 65535 - cxd2841er_read_agc_gain_i( |