- From: frank mori hess <fmhess_at_students.uiuc.edu>
- Date: Mon, 1 Jul 2002 17:18:33 -0500 (CDT)
On Mon, 1 Jul 2002, Dan Christian wrote: > As of version 0.7.65 (and CVS), I'm getting "buffer overfow" errors on > fast sampling. If I drop back to 0.7.64, then it runs fine. > > Above about 50K sample/second, it consistantly fails at exactly 40960 > samples (with a 64K buffer). If the input buffer is 32K, then it > happens at 24576 samples. At 128K, it happens at 73728 samples. > > With the 0.7.64 release, I can do 560K sample/sec without any problems. > CPU load isn't a problem in either case. The program is just reading > and discarding the data. > > The diffs in rtd520.c between those versions are trivial (spelling > fixes). > > Anybody have an idea what's broken? > > -Dan Christian > I probably broke it. I made some changes to try and make reading/writing to comedi's buffer more robust by going to a scheme that didn't make any assumptions about the relative priorities of the reader and writer. Actually, I wanted to go a little further than I did but I haven't yet... I only made changes to the comedi_buf_put/get macros and the core comedi read/write ioctls. So it's possible that drivers that did their own manipulation of the buffer might have gotten broken. I could probably convert your driver over to using comedi_buf_put() or comedi_buf_put_array() if you like. Frank
Received on 2002-07-01Z21:18:33