From 0e377819b99bf2290c94a0eec2be4443b4630ccd Mon Sep 17 00:00:00 2001 From: Klaus Schmidinger Date: Tue, 24 Jan 2012 05:33:53 -0300 Subject: [media] stb0899: fix the limits for signal strength values stb0899: fix the limits for signal strength values stb0899_read_signal_strength() adds an offset to the result of the table lookup. That offset must correspond to the lowest value in the lookup table, to make sure the result doesn't get below 0, which would mean a "very high" value since the parameter is unsigned. 'strength' and 'snr' need to be initialized to 0 to make sure they have a defined result in case there is no "internal->lock". Signed-off-by: Klaus Schmidinger Cc: Manu Abraham Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/frontends/stb0899_drv.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/dvb/frontends/stb0899_drv.c b/drivers/media/dvb/frontends/stb0899_drv.c index 097e706..dd08f4a 100644 --- a/drivers/media/dvb/frontends/stb0899_drv.c +++ b/drivers/media/dvb/frontends/stb0899_drv.c @@ -67,7 +67,7 @@ static const struct stb0899_tab stb0899_cn_tab[] = { * Crude linear extrapolation below -84.8dBm and above -8.0dBm. */ static const struct stb0899_tab stb0899_dvbsrf_tab[] = { - { -950, -128 }, + { -750, -128 }, { -748, -94 }, { -745, -92 }, { -735, -90 }, @@ -131,7 +131,7 @@ static const struct stb0899_tab stb0899_dvbs2rf_tab[] = { { -730, 13645 }, { -750, 13909 }, { -766, 14153 }, - { -999, 16383 } + { -950, 16383 } }; /* DVB-S2 Es/N0 quant in dB/100 vs read value * 100*/ @@ -964,6 +964,7 @@ static int stb0899_read_signal_strength(struct dvb_frontend *fe, u16 *strength) int val; u32 reg; + *strength = 0; switch (state->delsys) { case SYS_DVBS: case SYS_DSS: @@ -987,7 +988,7 @@ static int stb0899_read_signal_strength(struct dvb_frontend *fe, u16 *strength) val = STB0899_GETFIELD(IF_AGC_GAIN, reg); *strength = stb0899_table_lookup(stb0899_dvbs2rf_tab, ARRAY_SIZE(stb0899_dvbs2rf_tab) - 1, val); - *strength += 750; + *strength += 950; dprintk(state->verbose, FE_DEBUG, 1, "IF_AGC_GAIN = 0x%04x, C = %d * 0.1 dBm", val & 0x3fff, *strength); } @@ -1009,6 +1010,7 @@ static int stb0899_read_snr(struct dvb_frontend *fe, u16 *snr) u8 buf[2]; u32 reg; + *snr = 0; reg = stb0899_read_reg(state, STB0899_VSTATUS); switch (state->delsys) { case SYS_DVBS: -- cgit v1.1