Em Wed, 21 Jun 2017 21:45:43 +0200
Daniel Scheller <d.scheller.oss@xxxxxxxxx> escreveu:
> From: Daniel Scheller <d.scheller@xxxxxxx>
>
> Add signal-to-noise-ratio as provided by the demodulator in decibel scale.
> QAM/DVB-C needs some intlog calculation to have usable dB values, OFDM/
> DVB-T values from the demod look alright already and are provided as-is.
>
> Signed-off-by: Daniel Scheller <d.scheller@xxxxxxx>
> ---
> drivers/media/dvb-frontends/stv0367.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/drivers/media/dvb-frontends/stv0367.c b/drivers/media/dvb-frontends/stv0367.c
> index f8e9cceed04e..d3be25bc1002 100644
> --- a/drivers/media/dvb-frontends/stv0367.c
> +++ b/drivers/media/dvb-frontends/stv0367.c
> @@ -25,6 +25,8 @@
> #include <linux/slab.h>
> #include <linux/i2c.h>
>
> +#include "dvb_math.h"
> +
> #include "stv0367.h"
> #include "stv0367_defs.h"
> #include "stv0367_regs.h"
> @@ -2996,6 +2998,37 @@ static int stv0367ddb_set_frontend(struct dvb_frontend *fe)
> return -EINVAL;
> }
>
> +static void stv0367ddb_read_snr(struct dvb_frontend *fe)
> +{
> + struct stv0367_state *state = fe->demodulator_priv;
> + struct dtv_frontend_properties *p = &fe->dtv_property_cache;
> + int cab_pwr;
> + u32 regval, tmpval, snrval = 0;
> +
> + switch (state->activedemod) {
> + case demod_ter:
> + snrval = stv0367ter_snr_readreg(fe);
> + break;
> + case demod_cab:
> + cab_pwr = stv0367cab_snr_power(fe);
> + regval = stv0367cab_snr_readreg(fe, 0);
> +
> + /* prevent division by zero */
> + if (!regval)
> + snrval = 0;
> +
> + tmpval = (cab_pwr * 320) / regval;
> + snrval = ((tmpval != 0) ? (intlog2(tmpval) / 5581) : 0);
> + break;
> + default:
> + p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
> + return;
> + }
> +
> + p->cnr.stat[0].scale = FE_SCALE_DECIBEL;
> + p->cnr.stat[0].uvalue = snrval;
> +}
> +
> static void stv0367ddb_read_ucblocks(struct dvb_frontend *fe)
> {
> struct stv0367_state *state = fe->demodulator_priv;
> @@ -3042,10 +3075,12 @@ static int stv0367ddb_read_status(struct dvb_frontend *fe,
>
> /* stop if demod isn't locked */
> if (!(*status & FE_HAS_LOCK)) {
> + p->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
It sounds weird that CNR is only available with full lock.
On a very quick look at the driver, for SYS_DVBC_ANNEX_A, I suspect that
you will get CNR earlier. Probably when
cab_state->state == FE_CAB_CARRIEROK.
For SYS_DVBT, it seems that the algorithm doesn't have an intermediate
step. So, only after ter_state->state = FE_TER_LOCKOK you have full
lock.
So, you should likely apply something like the enclosed (untested) patch
to get more status from the frontend, at least for DVB-C.
Thanks,
Mauro
media: stv0367: Improve DVB-C frontend status
The stv0367 driver provide a lot of status on its state machine.
Change the logic to provide more information about frontend locking
status.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
diff --git a/drivers/media/dvb-frontends/stv0367.c b/drivers/media/dvb-frontends/stv0367.c
index f266c18c574c..9e5432b761b5 100644
--- a/drivers/media/dvb-frontends/stv0367.c
+++ b/drivers/media/dvb-frontends/stv0367.c
@@ -1507,7 +1507,8 @@ static int stv0367ter_read_status(struct dvb_frontend *fe,
*status = 0;
if (stv0367_readbits(state, F367TER_LK)) {
- *status |= FE_HAS_LOCK;
+ *status = FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI
+ | FE_HAS_SYNC | FE_HAS_LOCK;
dprintk("%s: stv0367 has locked\n", __func__);
}
@@ -2155,6 +2156,18 @@ static int stv0367cab_read_status(struct dvb_frontend *fe,
*status = 0;
+ if (state->cab_state->state > FE_CAB_NOSIGNAL)
+ *status |= FE_HAS_SIGNAL;
+
+ if (state->cab_state->state > FE_CAB_NOCARRIER)
+ *status |= FE_HAS_CARRIER;
+
+ if (state->cab_state->state >= FE_CAB_DEMODOK)
+ *status |= FE_HAS_VITERBI;
+
+ if (state->cab_state->state >= FE_CAB_DATAOK)
+ *status |= FE_HAS_SYNC;
+
if (stv0367_readbits(state, (state->cab_state->qamfec_status_reg ?
state->cab_state->qamfec_status_reg : F367CAB_QAMFEC_LOCK))) {
*status |= FE_HAS_LOCK;
