Re: [PATCH RFC 1/1] ASoC: fsl_ssi: Make fifo watermark and maxburst settings device tree options

From: Caleb Crome
Date: Thu Jan 14 2016 - 23:56:57 EST


On Thu, Jan 14, 2016 at 6:45 PM, Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote:
> On Thu, Jan 14, 2016 at 01:26:24PM -0800, Caleb Crome wrote:
>
>> As for optimal settings, I finally came to a setting of 4 for depth &
>> maxburst, which will result in more DMA requests, but it's the only
>> way that works at 48kHz for me. The default settings is 13 (15 - 2)
>> for the ones of the 15 item fifo, which is a pretty dramatic
>> difference. I just don't know if other chips will behave badly in
>> that case.
>
> What's your final configuration for TFWM0 bits, 4?

Yes, a value of 4 for my use case: i.MX6 @ 768000 words/second (48khz
* 16 channels).

Also, works at 8kHz, 16kHz 32 kHz.

A setting of 8 does not work reliably at 48kHz but does work at 8, 16 and 32.

-caleb