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Subjectmmap question (2.2.12)

Hello all,

I'm working on an mmapped version of the tulip driver under 2.2.12,
and I've got a couple of questions:

I've read here previously that bttv.c is a good example of how to do
this. I'm assigning the mmapped memory to the tulip chips, which PCI
Bus Master's the actual frame data into it.

Is this still the way to go? There's a note about user DMA being a
possibility, but I don't see anything else about it.

I didn't see any obvious limitation on size in the source (or through
man mmap()), but I am planning on doing ~30Mb using this. Is that a

The mmapping works to a large extent: the right data in the right
places most of the time, but I'm having a wierd frame-fragments
overlay problem (ie a chunk of a frame appearing over top of another
one). It repeats pretty well, but I haven't found the problem yet.

So I thought I would check my assumptions.



Richard Dynes

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