V4L/DVB (3266): Fix NICAM buzz on analog sound
Apparently, having the number of lines fixed at 4 reduces (or even kills) the buzz found in NICAM stereo with analog sound. Signed-off-by: Marcin Rudowski <mar_rud@poczta.onet.pl> Signed-off-by: Ricardo Cerqueira <v4l@cerqueira.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
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1 changed files with 6 additions and 4 deletions
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@ -787,12 +787,14 @@ static int set_pll(struct cx88_core *core, int prescale, u32 ofreq)
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int cx88_start_audio_dma(struct cx88_core *core)
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{
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/* constant 128 made buzz in analog Nicam-stereo for bigger fifo_size */
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int bpl = cx88_sram_channels[SRAM_CH25].fifo_size/4;
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/* setup fifo + format */
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cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH25], 128, 0);
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cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH26], 128, 0);
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cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH25], bpl, 0);
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cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH26], bpl, 0);
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cx_write(MO_AUDD_LNGTH, 128); /* fifo bpl size */
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cx_write(MO_AUDR_LNGTH, 128); /* fifo bpl size */
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cx_write(MO_AUDD_LNGTH, bpl); /* fifo bpl size */
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cx_write(MO_AUDR_LNGTH, bpl); /* fifo bpl size */
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/* start dma */
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cx_write(MO_AUD_DMACNTRL, 0x0003); /* Up and Down fifo enable */
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