[libdc1394-devel] Re: ieee1394 problem in DMA mode
Capture and control API for IIDC compliant cameras
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From: Justin H. <he...@cs...> - 2002-10-31 04:05:07
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I've confirmed this exact same problem, and the solution. We are running both sony and point grey cameras off of several linux boxes, each with >1 gig memory (dual processor systems) After adding the kernel option mem=512M, DMA capture started working. Before that, the dma routines would return black images. -justin > FROM: David Ergo > DATE: 10/07/2002 01:07:49 > SUBJECT: [libdc1394-devel] Re: ieee1394 problem in DMA mode > > > > Thank you Dan for your help, but I tested and the problem doesn't come > from a bus reset. > > After many tests, I found the conditions to have this unstable > configuration : > - PC with 1 GB RAM (I suppose that more RAM will have same effect) > - AND High Memory Support enabled in the kernel (4GB but I suppose that > 64GB will be the same) > I suppose this is a problem in the DMA routines or in the Memory Mapped >I/O. But I don't known if it's in libdc1394, in ieee1394 kernel modules > or in the kernel itself... > Could the libdc1394 & ieee1394 developpers check this please ? > >The temporary workaround is to have less than 1GB RAM or to disable High > Memory Support (but then you can't use the full GB RAM but only 896MB). > David |