Re: [alsa-devel] [PATCH V2] ASoC: tlv320aic3x: Fix codec pll configure bug
On Tue, Jun 26, 2012 at 14:31:42, Prchal Jiří wrote:
Hi Gururaja, shouldn't be better to use:
snd_soc_update_bits(codec, AIC3X_PLL_PROGA_REG, PLLP_MASK, pll_p);
instead of "read mask write" ?
Sure will resend the patch. Thanks for the review
Even at this place you don't need to keep rest of register (PLL_Q and PLL_enable), so yust writing is OK.
snd_soc_write(codec, AIC3X_PLL_PROGA_REG, pll_p << PLLP_SHIFT);
Dne 26.6.2012 08:03, Hebbar, Gururaja napsal(a):
In sound/soc/codecs/tlv320aic3x.c
data = snd_soc_read(codec, AIC3X_PLL_PROGA_REG); snd_soc_write(codec, AIC3X_PLL_PROGA_REG, data | (pll_p<< PLLP_SHIFT));
In the above code, pll-p value is OR'ed with previous value without clearing it. Bug is not seen if pll-p value doesn't change across Sampling frequency.
However on some platforms (like AM335x EVM-SK), pll-p may have different values across different sampling frequencies. In such case, above code configures the pll with a wrong value. Because of this bug, when a audio stream is played with pll value different from previous stream, audio is heard as differently.
Signed-off-by: Hebbar, Gururajagururaja.hebbar@ti.com
chnages in V2: modify subject to indicate ASOC and codec as tlv320aic3x
sound/soc/codecs/tlv320aic3x.c | 2 +- sound/soc/codecs/tlv320aic3x.h | 1 + 2 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/sound/soc/codecs/tlv320aic3x.c b/sound/soc/codecs/tlv320aic3x.c index d0dbac1..8c1977b 100644 --- a/sound/soc/codecs/tlv320aic3x.c +++ b/sound/soc/codecs/tlv320aic3x.c @@ -963,7 +963,7 @@ static int aic3x_hw_params(struct snd_pcm_substream *substream, }
found:
- data = snd_soc_read(codec, AIC3X_PLL_PROGA_REG);
- data = snd_soc_read(codec, AIC3X_PLL_PROGA_REG)& ~PLLP_MASK; snd_soc_write(codec, AIC3X_PLL_PROGA_REG, data | (pll_p<< PLLP_SHIFT)); snd_soc_write(codec, AIC3X_OVRF_STATUS_AND_PLLR_REG,
diff --git a/sound/soc/codecs/tlv320aic3x.h b/sound/soc/codecs/tlv320aic3x.h index 06a1978..16d9999 100644 --- a/sound/soc/codecs/tlv320aic3x.h +++ b/sound/soc/codecs/tlv320aic3x.h @@ -166,6 +166,7 @@
/* PLL registers bitfields */ #define PLLP_SHIFT 0 +#define PLLP_MASK 7 #define PLLQ_SHIFT 3 #define PLLR_SHIFT 0 #define PLLJ_SHIFT 2
Regards, Gururaja
participants (1)
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Hebbar, Gururaja