On Mon, Oct 19, 2015 at 05:42:23PM -0700, Stefan Agner wrote:
When using the Rx clock for both, transmitter and receiver, the transmitter needs to be set to synchronous with receiver.
This reverts 855675f6e6a6 ("ASoC: fsl_sai: Set SYNC bit of TCR2 to Asynchronous Mode"), which, judiging from the commit log, seems to mixed up between the two synchronous modes: The boolean
Actually my original patch I sent to the mail list was different: http://mailman.alsa-project.org/pipermail/alsa-devel/2014-August/079639.html
It should be applied before the asynchronous patches however they are somehow disordered. I guess that's why now the commit appears in such confusing way. But anyway it's a bug I should have noticed long time ago.
Thanks a lot
sai->synchronous[TX] is indicating wheather the SAI should work in Rx synchronous mode (sync Tx with Rx), hence if the value is true, the SYNC field of TCR2 needs to be set to 0x1 ("Synchronous with receiver").
Signed-off-by: Stefan Agner stefan@agner.ch
Acked-by: Nicolin Chen nicoleotsuka@gmail.com
Hi Nicolin,
I got this reported from a customer, he tried to use the device tree property "fsl,sai-synchronous-rx" according to the description but it failed. In a quick test, setting the SYNC field of TCR2 to 0x1 helped in his case. So I think this here is right. But given that you chaged the very same line can you review that again and give me a Ack/Nack?
-- Stefan
sound/soc/fsl/fsl_sai.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c index a18fd92..1f0e552 100644 --- a/sound/soc/fsl/fsl_sai.c +++ b/sound/soc/fsl/fsl_sai.c @@ -454,7 +454,8 @@ static int fsl_sai_trigger(struct snd_pcm_substream *substream, int cmd, * Rx sync with Tx clocks: Clear SYNC for Tx, set it for Rx. * Tx sync with Rx clocks: Clear SYNC for Rx, set it for Tx. */
- regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC, 0);
- regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC,
sai->synchronous[TX] ? FSL_SAI_CR2_SYNC : 0);-- 2.6.1