Re: [PARPORT] Question about 2.4.0-test1 FIFO reads

From: rjh@world.std.com
Date: Wed Jul 05 2000 - 11:05:35 EDT

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    On 3 Jul, Tim Waugh wrote:
    > On Sun, Jul 02, 2000 at 05:13:28PM -0400, rjh@world.std.com wrote:
    >
    >> 1) This assumes that the stop, turn around is fast enough to avoid a few
    >> extra bytes getting into the FIFO. (The code checks for this and
    >> reports an error when it happens.)
    >
    > Yes. I wonder if it works to stop it before reading from the FIFO,
    > and then resume if we need more. That would close that race wouldn't
    > it?
    >

    Further ooops. According to the Winbond part specification (used in the
    mobo that I am testing), you should wait for the FIFO to drain empty
    before switching directions. Unspecified improper behavior may result
    if you don't wait. So, early switch is *not* a good idea after all.

    R Horn

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