Date: Fri, 04 Sep 2009 00:21:10 +0300 From: Alexander Motin <mav@FreeBSD.org> To: Ryan Rogers <webmaster@doghouserepair.com>, current@FreeBSD.org Subject: Re: non aligned DMA transfer attempted Message-ID: <4AA03346.5010608@FreeBSD.org> In-Reply-To: <h7p0a3$k3m$1@FreeBSD.cs.nctu.edu.tw> References: <h7p0a3$k3m$1@FreeBSD.cs.nctu.edu.tw>
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Ryan Rogers wrote: > I'm having a bit of a problem getting my DVD drive(s) to work correctly. > I'm trying to transfer my DVD collection to my media server, but > whenever I run vobcopy, /var/log/messages gets spammed with: > > acd0: FAILURE - non aligned DMA transfer attempted > acd0: setting up DMA failed > > I added a bit more information to the first message to see if I could > figure out what was actually going on. request->data was 0xd40e0c37, > ch->dma.alignment was 2, and request->bytecount was 2048. Actually I don't understand what for this check was made there. It is busdma infrastructure business to implement buffer bouncing to manage requested alignment. But this check enforces application level to bother with this. Usually it works fine, as memory often allocated aligned. But probably here is some specifics in your application. Could you try to just to comment-out that request->data check? -- Alexander Motin
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