- From: Rolf Mueller <rolf.mueller_at_uni-tuebingen.de>
- Date: Fri, 22 Nov 2002 17:38:50 +0100
Hi Frank, thank you so much again for your invaluable help in getting comedi to work with our 611x boards. I hope you had a pleasant trip back to the US. I notice that your recent changes (2002/11/19) in the DMA underrun detection result in "DMA underrun" errors being triggered for all but ridiculously low conversion frequencies (100 Hz or so). What typically happens is that nbytes (from mite_bytes_read) is a bit larger than devpriv->last_buf_write_count, whereas the latter is always 8192, the former is something like 8212, 8216, 8248, 8252. However, with the pre-2002/11/19 I do not see any hick-ups in the waveform that would indicate a problem. It also appears to me that the ai-munging is not done correctly or consistently, signed numbers seem to be treated as unsigned, this does not seem to be a problem of the user application, because it occurs with cmd and ktimetrace likewise. Best wishes, Rolf -- Rolf Mueller, rolf.mueller_at_uni-tuebingen.de Biosonar Lab, Tuebingen University, Morgenstelle 28, 72076 Tuebingen Phone +49 7071 29-74838 Fax. +49 7071 292618
Received on 2002-11-22Z16:38:50