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Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!haven.umd.edu!uunet!pipex!uknet!mcsun!sunic!osiris.kbfi.ee!anubis.kbfi.ee!margus From: margus@anubis.kbfi.ee (MArgus Liiv) Newsgroups: comp.os.386bsd.questions Subject: Problem with DMA (may be FAQ) Date: 7 Jul 1993 14:50:56 GMT Organization: Institute of Chemical Physics and Biophysics, Estonia Lines: 20 Message-ID: <21ensg$8qu@osiris.kbfi.ee> NNTP-Posting-Host: anubis.kbfi.ee X-Newsreader: TIN [version 1.1 PL8] I have a problem with reading DMA on AT486 in NetBSD 0.8. (DRQ=6) I had defined in device driver description a static area static char mxq[BUFSIZE]; /* BUFSIZE == 1024 */ In mxintr-routine is defined call to DMA: isa_dmastart( B_READ, mxq, mxcount, mxDMA_CH ); /* DRQ=6, mxcount=1 */ In the same routine at END_OF_DMA-interrupt is defined: isa_dmadone( B_READ, mxq, mxcount, mxDMA_CH ); After this command stays mxq-buffer unaffected and sometimes is possible system crush. How allocate memory for high numbers of DMA-channels? Please send answers with mail to address: ml@mars.aai.ee I will collect these answers and write a summary over answers (if neccesary). Thank you very much Sincerely yours Margus.