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

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

Dear Friends,

I found the machine driver to be working after modification in setting
up the proper clock divisor. Please find the working driver at
http://pastebin.com/i5PrFxC7.

Now, when I try to run the aplay utility, I got into following error:
aplay: set_params:1172: not enough memory

After debugging I found that the function
snd_pcm_hw_params_get_period_size(params, &chunk_size, 0); call under
set_params() function returns the value of chunk_size to zero. Thus
realloc fails and returns the above error.

I came across following link
http://mailman.alsa-project.org/pipermail/alsa-devel/2009-February/014976.html
 who faced the same problem. Can any one suggest some light on why it
is happening? I am using alsa-lib & alsa-utils version 1.0.23 on
AT91SAM9 processor using buildroot.

Have a Good Day,
Thank you,
Ankur.


On Tue, Aug 16, 2011 at 12:19 PM, Ankur Patel <con...@gm...> wrote:
> 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.
>