Re: [PARPORT] DMA and the parallel port

From: Bob Tanner (
Date: Fri May 02 2003 - 23:40:51 EDT

  • Next message: Blaise Gassend: "Re: [PARPORT] DMA and the parallel port"

    On Friday 02 May 2003 08:38 pm, Blaise Gassend wrote:
    > There is some DMA code in parport_pc.c. For writing to the port it works
    > well. For reading from the port there is some code that I hacked up that
    > is circulating with the CPiA webcam drivers, but it only works for those
    > webcams. For the webcam it produces a HUGE improvement in performance.
    > What exactly are you trying to do?

    Writing bytes to a custom piece of hardware. Speed is #1 priority and dma was
    brought up as a factor in speed.

    It's a bit if a screwy situation, since the code is in user-space, and I'd
    think a kernel driver would be much faster.

    Bob Tanner <>         | Phone : (952)943-8700, Minnesota, Linux | Fax   : (952)943-8500             | Linux Just Works!         
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