[PATCH 040/141] V4L/DVB (3266): Fix NICAM buzz on analog sound

mchehab
2006-03-20T16:08:29Z

From: Marcin Rudowski <mar_rud@poczta.onet.pl>
Date: 1139224514 -0200

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>
---

diff --git a/drivers/media/video/cx88/cx88-core.c b/drivers/media/video/cx88/cx88-core.c
diff --git a/drivers/media/video/cx88/cx88-core.c b/drivers/media/video/cx88/cx88-core.c
index 8d6d6a6..3720f24 100644
--- a/drivers/media/video/cx88/cx88-core.c
+++ b/drivers/media/video/cx88/cx88-core.c
@@ -787,12 +787,14 @@ static int set_pll(struct cx88_core *cor

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 */