V4L/DVB (9315): s5h1411: Skip reconfiguring demod modulation if already at the desired modulation
If we are already at the desired modulation, there is no need to reconfigure the demod (at a tuning time cost) Note that this change revealed that although the datasheet says the demod starts out in VSB-8 mode, the first tuning was failing consistently unless we went through the work of setting the registers. So add a field to denote this case so we always do the enable_frontend call, even if the first tuning request is for VSB-8. Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com> Reviewed-by: Michael Krufky <mkrufky@linuxtv.org> Acked-by: Steven Toth <stoth@linuxtv.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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@ -38,6 +38,7 @@ struct s5h1411_state {
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struct dvb_frontend frontend;
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struct dvb_frontend frontend;
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fe_modulation_t current_modulation;
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fe_modulation_t current_modulation;
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unsigned int first_tune:1;
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u32 current_frequency;
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u32 current_frequency;
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int if_freq;
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int if_freq;
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@ -489,6 +490,12 @@ static int s5h1411_enable_modulation(struct dvb_frontend *fe,
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dprintk("%s(0x%08x)\n", __func__, m);
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dprintk("%s(0x%08x)\n", __func__, m);
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if ((state->first_tune == 0) && (m == state->current_modulation)) {
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dprintk("%s() Already at desired modulation. Skipping...\n",
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__func__);
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return 0;
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}
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switch (m) {
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switch (m) {
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case VSB_8:
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case VSB_8:
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dprintk("%s() VSB_8\n", __func__);
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dprintk("%s() VSB_8\n", __func__);
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@ -513,6 +520,7 @@ static int s5h1411_enable_modulation(struct dvb_frontend *fe,
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}
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}
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state->current_modulation = m;
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state->current_modulation = m;
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state->first_tune = 0;
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s5h1411_softreset(fe);
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s5h1411_softreset(fe);
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return 0;
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return 0;
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@ -622,6 +630,11 @@ static int s5h1411_init(struct dvb_frontend *fe)
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/* The datasheet says that after initialisation, VSB is default */
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/* The datasheet says that after initialisation, VSB is default */
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state->current_modulation = VSB_8;
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state->current_modulation = VSB_8;
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/* Although the datasheet says it's in VSB, empirical evidence
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shows problems getting lock on the first tuning request. Make
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sure we call enable_modulation the first time around */
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state->first_tune = 1;
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if (state->config->output_mode == S5H1411_SERIAL_OUTPUT)
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if (state->config->output_mode == S5H1411_SERIAL_OUTPUT)
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/* Serial */
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/* Serial */
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s5h1411_set_serialmode(fe, 1);
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s5h1411_set_serialmode(fe, 1);
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