[media] stb0899: store successful inversion for next run

Usually, inversion doesn't change in a system. Storing the last
successful inversion value speeds up tuning of DVB-S2 transponders.

Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 9 insertions, 4 deletions

diff --git a/drivers/media/dvb-frontends/stb0899_algo.c b/drivers/media/dvb-frontends/stb0899_algo.c
index e0d31a2ea578..4b49efb67931 100644
--- a/drivers/media/dvb-frontends/stb0899_algo.c
+++ b/drivers/media/dvb-frontends/stb0899_algo.c
@@ -1488,9 +1488,15 @@ enum stb0899_status stb0899_dvbs2_algo(struct stb0899_state *state)
 
                 offsetfreq = offsetfreq / ((1 << 30) / 1000);
                 offsetfreq *= (internal->master_clk / 1000000);
+
+                /* store current inversion for next run */
                 reg = STB0899_READ_S2REG(STB0899_S2DEMOD, DMD_CNTRL2);
                 if (STB0899_GETFIELD(SPECTRUM_INVERT, reg))
-                        offsetfreq *= -1;
+                        internal->inversion = IQ_SWAP_ON;
+                else
+                        internal->inversion = IQ_SWAP_OFF;
+
+                offsetfreq *= internal->inversion;
 
                 internal->freq = internal->freq - offsetfreq;
                 internal->srate = stb0899_dvbs2_get_srate(state);
diff --git a/drivers/media/dvb-frontends/stb0899_drv.c b/drivers/media/dvb-frontends/stb0899_drv.c
index b3ccd3dbbda1..82391feb6839 100644
--- a/drivers/media/dvb-frontends/stb0899_drv.c
+++ b/drivers/media/dvb-frontends/stb0899_drv.c
@@ -1618,19 +1618,18 @@ static struct dvb_frontend_ops stb0899_ops = {
 struct dvb_frontend *stb0899_attach(struct stb0899_config *config, struct i2c_adapter *i2c)
 {
         struct stb0899_state *state = NULL;
-        enum stb0899_inversion inversion;
 
         state = kzalloc(sizeof (struct stb0899_state), GFP_KERNEL);
         if (state == NULL)
                 goto error;
 
-        inversion                               = config->inversion;
         state->verbose                          = &verbose;
         state->config                           = config;
         state->i2c                              = i2c;
         state->frontend.ops                     = stb0899_ops;
         state->frontend.demodulator_priv        = state;
-        state->internal.inversion               = inversion;
+        /* use configured inversion as default -- we'll later autodetect inversion */
+        state->internal.inversion               = config->inversion;
 
         stb0899_wakeup(&state->frontend);
         if (stb0899_get_dev_id(state) == -ENODEV) {