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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>
Marcin Rudowski 19 years ago
parent
commit
17801f5fa2
1 changed files with 6 additions and 4 deletions
  1. 6 4
      drivers/media/video/cx88/cx88-core.c

+ 6 - 4
drivers/media/video/cx88/cx88-core.c

@@ -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 */