V4L/DVB (9457): Optimization, Fix a Bug

* cut down some I/O operations by disabling "disable gate"
* budget_av was left with the gate open, thereby more susceptible
to RF interference due to I/O operations

Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 20 insertions, 2 deletions

diff --git a/drivers/media/dvb/frontends/stb0899_drv.c b/drivers/media/dvb/frontends/stb0899_drv.c
index 196a837f11ce..333b983b04ab 100644
--- a/drivers/media/dvb/frontends/stb0899_drv.c
+++ b/drivers/media/dvb/frontends/stb0899_drv.c
@@ -1241,7 +1241,7 @@ static int stb0899_set_tone(struct dvb_frontend *fe, fe_sec_tone_mode_t tone)
         return 0;
 }
 
-static int stb0899_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
+int stb0899_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
 {
         int i2c_stat;
         struct stb0899_state *state = fe->demodulator_priv;
@@ -1255,10 +1255,15 @@ static int stb0899_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
                 i2c_stat |=  STB0899_I2CTON;
                 if (stb0899_write_reg(state, STB0899_I2CRPT, i2c_stat) < 0)
                         goto err;
+        } else {
+                dprintk(state->verbose, FE_DEBUG, 1, "Disabling I2C Repeater ...");
+                i2c_stat &= ~STB0899_I2CTON;
+                if (stb0899_write_reg(state, STB0899_I2CRPT, i2c_stat) < 0)
+                        goto err;
         }
         return 0;
 err:
-        dprintk(state->verbose, FE_ERROR, 1, "I2C Repeater enable failed");
+        dprintk(state->verbose, FE_ERROR, 1, "I2C Repeater control failed");
         return -EREMOTEIO;
 }
 
@@ -1592,10 +1597,17 @@ static enum dvbfe_search stb0899_search(struct dvb_frontend *fe, struct dvbfe_pa
                         internal->derot_percent = 30;
 
                         /* What to do for tuners having no bandwidth setup ?    */
+                        /* enable tuner I/O */
+                        stb0899_i2c_gate_ctrl(&state->frontend, 1);
+
                         if (state->config->tuner_set_bandwidth)
                                 state->config->tuner_set_bandwidth(fe, (13 * (stb0899_carr_width(state) + SearchRange)) / 10);
                         if (state->config->tuner_get_bandwidth)
                                 state->config->tuner_get_bandwidth(fe, &internal->tuner_bw);
+
+                        /* disable tuner I/O */
+                        stb0899_i2c_gate_ctrl(&state->frontend, 0);
+
                         /* Set DVB-S1 AGC               */
                         stb0899_write_reg(state, STB0899_AGCRFCFG, 0x11);
 
@@ -1624,11 +1636,17 @@ static enum dvbfe_search stb0899_search(struct dvb_frontend *fe, struct dvbfe_pa
                         internal->srate                 = i_params->srate;
                         internal->srch_range            = SearchRange;
 
+                        /* enable tuner I/O */
+                        stb0899_i2c_gate_ctrl(&state->frontend, 1);
+
                         if (state->config->tuner_set_bandwidth)
                                 state->config->tuner_set_bandwidth(fe, (stb0899_carr_width(state) + SearchRange));
                         if (state->config->tuner_get_bandwidth)
                                 state->config->tuner_get_bandwidth(fe, &internal->tuner_bw);
 
+                        /* disable tuner I/O */
+                        stb0899_i2c_gate_ctrl(&state->frontend, 0);
+
 //                      pParams->SpectralInv            = pSearch->IQ_Inversion;
 
                         /* Set DVB-S2 AGC               */