Hi, could you share the code of your project? I'm trying to connect only one ADC to the beaglebone (pcm1803) and i cant get it registered by alsa. I wrote a custom codec driver, and modified davinci.evm.c. Any help would be appreciated. Thanks! Regards
El jueves, 14 de marzo de 2013 10:12:47 UTC-3, ChrisSchuku escribió: > > Hi, > > I'm capturing an 8-channel TDM stream (32 bit slots) on the BeagleBone > running Ubuntu. My problem is, that when CPU is under heavy load, channels > are swapping like crazy (ie. signal from channel one is suddenly on channel > 8, then on 5, ...). > Analyzing the recorded stream I found that the reason for this is that > sometimes one time-slot within a frame is missing (is skipped). Since this > behaviour correlates with the CPU load, I'm pretty sure that it's not the > codec that messes up the TDM stream. Rather I suspect the problem to be on > the McASP or EDMA side of the ALSA driver. > Unfortunately I really have no idea how to track down this problem further > - I only know that somewhere along the way from the McASP input pins to the > ALSA API some timeslots (1 slot is 4 Byte long) get lost. > > Has anyone ever experienced similar behaviour or can anyone suggest a way > to debug this problem (I can't seem to get any hints from kernel messages > on this)? > > Btw: It seems to me, that currently ping/pong buffering is not being used > as davinci_pcm_enqueue_dma (sound/soc/davinci/davinci-pcm.c) is called on > every DMA interrupt. Is that something to look into? > > Any suggestion are very much appreciated! > > best, > Chris > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
