[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 <Klaus.Schmidinger@tvdr.de>
Cc: Manu Abraham <abraham.manu@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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 @@
* 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 @@
{ -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 @@
int val;
u32 reg;
+ *strength = 0;
switch (state->delsys) {
case SYS_DVBS:
case SYS_DSS:
@@ -987,7 +988,7 @@
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 @@
u8 buf[2];
u32 reg;
+ *snr = 0;
reg = stb0899_read_reg(state, STB0899_VSTATUS);
switch (state->delsys) {
case SYS_DVBS: