Problems with the NI PCI-6110

I’m running comedi 0.7.69 and comedilib 0.7.22 on kernel 2.6.8.1-x86_64, 
my daq is a ni pci-6110.

I have seen the traffic over the past few days to Phil Blackers problem 
with the ni6036, and some of mine are similar.

When I try to create a loop to either use the polling technique or the 
mmap techniques shown in the demo’s to sample 1 to 3 channels of analog 
input at 4Mhz I get near 2048 to 4096 samples and then get errors like: 
“kernel: ni_mio_common: DMA overwrite of free area”
For the polling I am calling a standard read call. I’ve tried adjusting 
the size of the buffer passed into the read from very small to very 
large values, noticing no difference. I have inserted a lot of output 
from functions like comedi_get_buffer_contents, and it seems the buffer 
in both the mmap and poll cases gets to 0 and never resets. Calling 
comedi_mark_buffer_read with the current position of the buffer that has 
been read doesn’t seem to effect the status either.

When running the polling program with DEBUG_MITE, DEBUG_INTERRUPT, 
DEBUG_STATUS_A and DEBUG_STATS_B gives the following output:

kernel: ni_ai_cmd
kernel: Interrupt_A_Enable_Register = 0x0021
kernel: mite_prep_dma ch0
kernel: ni_mio_common: interrupt: a_status=80f2 m0_status=00a00000
kernel: A status: fifo_empty
kernel: exit mite_prep_dma
kernel: mite_dma_arm ch0
kernel: mite_dma_tcr ch0, lkar=0x7fc4db80 tcr=0
kernel: exit ni_ai_cmd
kernel: ni_mio_common: SC_TC interrupt
kernel: ni_mio_common: interrupt: a_status=80f2 m0_status=00800040
kernel: A status: interrupt_a start1 sc_tc start stop fifo
kernel: A status: fifo_empty

I get similar output from the mmap case as well. Anyone more familiar 
with the ni drivers know of a way to keep the fifo from draining like it 
is? I am perplexed
As what to do since I know the card is capable of sampling at this speed 
with the windows drivers and in labview.

Thanks,

Doug

-- 
==============================
Doug Farley

Safety Critical Avionics Systems Branch 
NASA Langley Research Center

< D.L.FARLEY_at_LaRC.NASA.GOV > 
< Phone +1 757 864-8141 >

Received on 2004-12-23Z16:25:10