imx8mmini sai1 max sample rates

[sofia_0571]

hi

    sai1 connect a codecs support sample rates 768khz/32bit. SAI1-RX0 connect codec_DOUT.

have no data with 768khz/32bit and L/R channels to read.but SAI1-TXFS/SAI1-TXC could output 768khz/49.152Mhz. read L/R channels with 768khz/16bit and 384khz/32bit is ok.kernel version 6.1.36.

thanks.

[JorgeCas]

Hello,

Could you please share your device tree configuration?

Which CODEC are you using?

Best regards.

[sofia_0571]

about codecs dts as below:

run arecord cmd with "-f S32_LE -r 384000 -c 2 -d 1 test.wav" or "-f S16_LE -r 786000 -c 2 -d 1 test.wav" is ok. but run with "-f S32_LE -r 768000 -c 2 -d 1 test.wav",test.wav is NULL.

[JorgeCas]

Hello,

If you are getting errors related to the sample rate, could be caused by clock source since it is not able to generate the necessary frequency for that sample rate.

Sometimes, is needed to use a dedicated clock source such as an external clock to get an specific sample rate.

Best regards.

[sofia_0571]

when read with 768kHz 32bit x 2 channel,SAI1_TXFS/SAI1_TXC output is ok(768khz/49.152Mhz),The codec data output pin (connect to SAI1_RX0)has data output when checked with an oscilloscope.Is it possible that imx8mmini sdma is not worKing?

[JorgeCas]

Hello,

Do you get underflow or overflow errors during testing?

Best regards.

[sofia_0571]

get kernel print errors during testing as below:
[ 506.336480] [858] wait_for_avail:1936: asoc-simple-card sound-pcmdev: capture write error (DMA or IRQ trouble?)

[JorgeCas]

Hello,

Please share your dmesg:

dmesg | grep -i -E "xrun|overrun|dma|fifo|sdma|sai"

With that error log the issue could be caused by an overrun, please try to increase period and buffer size, for example:

arecord -D hw:0,0 -f S32_LE -r 768000 -c 2 --buffer-size=65536 --period-size=8192 -d 5 test.wav

Best regards.