[Alsa-user] WM8727 & AT91SAM9G45: DMA or IRQ trouble

[Ankur P. <con...@gm...>]

Dear Friends,

I am using WM8727 codec with AT91SAM9G45 processor. I have implemented
machine code as http://pastebin.com/axadqGhd . I found over the web
that the SSC driver from Atmel and WM8727 Codec driver works fine as
couple of ppl have used it successfully. I guess the issue should be
in the machine driver.

After insterting the module I got following output:
# insmod sam9g45_wm8727.ko
atmel-pcm:preallocate_dma_buffer: area=ffadf000, addr=77c40000, size=32768
asoc: WM8727 <-> atmel-ssc0 mapping ok

I am getting error while running "cat /dev/urandom > /dev/audio" and found
following output :
# cat /dev/urandom > /dev/audio
atmel_ssc_startup: SSC_SR=0x204
atmel_ssc_hw_params: RCMR=00010721 RFMR=0000008f TCMR=00010702 TFMR=0000008f
atmel_ssc_dai: Starting clock
atmel_ssc_dai,hw_params: SSC initialized
atmel-pcm: hw_params: DMA for SSC0 PCM out initialized
(dma_bytes=32768, period_size=8192)
transmit enabled SSC_SR=0x000104cf
atmel-pcm:buffer_size = 8192,dma_area = ffac1000, dma_bytes = 32768
atmel-pcm: trigger: period_ptr=77962000, xpr=2006319104, xcr=4096,
xnpr=2006327296, xncr=4096
sr=65731 imr=0
ALSA sound/core/pcm_lib.c:1708: playback write error (DMA or IRQ trouble?)
ALSA sound/core/pcm_lib.c:1708: playback write error (DMA or IRQ trouble?)
cat: write error: Input/output error
ALSA sound/core/pcm_native.c:1482: playback drain error (DMA or IRQ trouble?)
atmel-pcm:buffer_size = 8192,dma_area = ffac1000, dma_bytes = 32768
atmel_ssc_shutdown: transmit disabled SSC_SR=0x000000c0
atmel_ssc_dau: Stopping clock

Any suggestions/thoughts will be helpful.

Note: I have posted the question alsa-devel but later on I found that
it is for the enhancement for the drivers so I am posting it on the
alsa-user mailing list.

Have a Good Day,
Thank you,
Ankur.