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V4L/DVB (3266): Fix NICAM buzz on analog sound
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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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Marcin Rudowski authored and Mauro Carvalho Chehab committed Feb 6, 2006
1 parent bbab6fd commit 17801f5
Showing 1 changed file with 6 additions and 4 deletions.
10 changes: 6 additions & 4 deletions drivers/media/video/cx88/cx88-core.c
Original file line number Diff line number Diff line change
Expand Up @@ -787,12 +787,14 @@ static int set_pll(struct cx88_core *core, int prescale, u32 ofreq)

int cx88_start_audio_dma(struct cx88_core *core)
{
/* constant 128 made buzz in analog Nicam-stereo for bigger fifo_size */
int bpl = cx88_sram_channels[SRAM_CH25].fifo_size/4;
/* setup fifo + format */
cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH25], 128, 0);
cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH26], 128, 0);
cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH25], bpl, 0);
cx88_sram_channel_setup(core, &cx88_sram_channels[SRAM_CH26], bpl, 0);

cx_write(MO_AUDD_LNGTH, 128); /* fifo bpl size */
cx_write(MO_AUDR_LNGTH, 128); /* fifo bpl size */
cx_write(MO_AUDD_LNGTH, bpl); /* fifo bpl size */
cx_write(MO_AUDR_LNGTH, bpl); /* fifo bpl size */

/* start dma */
cx_write(MO_AUD_DMACNTRL, 0x0003); /* Up and Down fifo enable */
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