I am new to alsa development, but I am trying to write a alsa capture driver for a DAC. The driver is based on at73c213 since it will be running on AVR32 and using the SSC bus. The driver is running on a NGW100 card and I am using buildroot provided by Atmel. The alsa version is 1.0.14a and the kernel is 2.6.23.

The DAC is not using any configuration bus so I have switched to using platform_* functions instead of dev/spi (grabbed from snd-dummy). I have also been taking some capture pieces from the snd-dummy driver.

I am now stuck with two problems: 1) When using arecord -L, I only get the "null" device 2) When I try to use arecord to do a recording I get "arecord: set_params:1039: unable to install sw params:". I get the same message when trying to use the snd-dummy driver, even though this driver also has PCM device.

Any hints on how to proceed?

I can post the driver source if that is interesting.

Best regards William Juul

Listings (annotated):

# modprobe -v snd-dummy Loading module snd-page-alloc Loading module soundcore Loading module snd Loading module snd-timer Loading module snd-pcm Loading module snd-dummy # # # arecord -l **** List of CAPTURE Hardware Devices **** card 0: Dummy [Dummy], device 0: Dummy PCM [Dummy PCM] Subdevices: 8/8 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 Subdevice #2: subdevice #2 Subdevice #3: subdevice #3 Subdevice #4: subdevice #4 Subdevice #5: subdevice #5 Subdevice #6: subdevice #6 Subdevice #7: subdevice #7 # # arecord -L default:CARD=Dummy Dummy, Dummy PCM Default Audio Device null Discard all samples (playback) or generate zero samples (capture) # # # # arecord > dummy.wav Recording WAVE 'stdin' : Unsigned 8 bit, Rate 8000 Hz, Mono pcm->setup: 1 stream : CAPTURE access : RW_INTERLEAVED format : U8 subformat : STD channels : 1 rate : 8000 exact rate : 8000 (8000/1) msbits : 8 buffer_size : 355 period_size : 355 period_time : 44375 tick_time : 4000 tstamp_mode : NONE period_step : 1 sleep_min : 0 avail_min : 355 xfer_align : 355 start_threshold : 1 stop_threshold : 355 silence_threshold: 0 silence_size : 0 boundary : 1488977920 arecord: set_params:1039: unable to install sw params: start_mode: DATA xrun_mode: STOP tstamp_mode: NONE period_step: 1 sleep_min: 0 avail_min: 0 xfer_align: 0 silence_threshold: 0 silence_size: 0 boundary: 1488977920 # # # arecord -r 22786 -c 1 -f U8 -s 1 -A 100 -v > dummy.wav # (This works OK) # # reboot ... # # # modprobe -v snd-ads127x Loading module soundcore Loading module snd Loading module snd-page-alloc Loading module snd-timer Loading module snd-pcm Loading module snd-ads127x snd_ads127x_probe OK # # # arecord -l **** List of CAPTURE Hardware Devices **** card 0: ads127x_0 [AVR32 NGW100 external DAC], device 0: ads127x [ads127x] Subdevices: 1/1 Subdevice #0: subdevice #0 # arecord -L null Discard all samples (playback) or generate zero samples (capture) # # # # # arecord -r 22786 -c 1 -f S24_LE -s 1 -A 100 > ads127x.wav ALSA /home/williaj/src/ads127x/src/ads127x.c:141: snd_ads127x_pcm_open Recording WAVE 'stdin' : Signed 24 bit Little Endian, Rate 22786 Hz, Mono pcm->setup: 1 stream : CAPTURE accessALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 : RW_INTERLEAVED format : S24_LEALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3

subformat : STD channels : 1 raALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 te : 22786 exact rate : 22786 (22786/1) msbits : 32 buffer_size : 4044 period_size : 1011 period_time : 44369 tick_time ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 : 4000 tstamp_mode : NONE period_step ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 : 1 sleep_min : 0 ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3

xfer_align : 1011 start_threshold : 1 ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 stop_threshold : 4044 silence_threshold: ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 0 silence_size : 0 boundary : 21202206ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 72 overrun!!! (at least 1.074 ms long) overrun!!! (at least 0.151 ms long) overrun!!! (at least 0.139 ms long) overrun!!! (at least 0.141 ms long) overrALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 un!!! (at least 0.142 ms long) overrun!!! (at lALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 east 0.139 ms long) overrun!!! (at least 0.137 ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 ms long) overrun!!! (at least 0.139 ms long) oALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 verrun!!! (at least 0.138 ms long) overrun!!! (ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 at least 0.149 ms long) overrun!!! (at least 0.ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 145 ms long) overrun!!! (at least 0.154 ms long) overrun!!! (at least 0.146 ms long) overrun!!! (at least 0.146 ms long) overrun!!! (at least 0.724 ms loALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 ng) overrun!!! (at least 0.152 ms long) ALSA sound/core/pcm_lib.c:155: BUG: stream = 1, pos = 0x3b5f034, buffer size = 0xfcc, period size = 0x3f3 overrun!!! (at least 0.125 ms long)