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    SubjectRe: IDE-flash device and hard disk on same controller
    Jeff Garzik <> writes:

    > Eric W. Biederman wrote:
    > > I don't see any checking for the ATA bsy flag before you start sending
    > > commands. I have seen the current IDE code fail too many times if I
    > > boot to fast, because of a lack of this one simple test. So I don't
    > > see how this could be considered a proper probe.
    > There is no ATA bsy flag check at only one point, and that is before EXECUTE
    > DEVICE DIAGNOSTIC is issued. The idea with this command is that it pretty much
    > stomps up and down the ATA bus, trouncing ongoing activity in the process.

    The problem is that immediately after bootup ATA devices do not respond until
    their media has spun up. Which is both required by the spec, and observed in
    practice. Which is likely a problem if this code is run a few seconds after
    bootup. Which makes it quite possible the drive will ignore the EXECUTE DEVICE
    DIAGNOSTICS and your error code won't be valid when the bsy flag
    clears. I don't know how serious that would be.

    I can test and find out but I would rather confine my testing to
    commands that look like they will stay within the realms of
    predictable behavior.

    And yes with LinuxBIOS I can reliably boot up fast enough to make this
    problem show up in practice.

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      Last update: 2005-03-22 13:28    [W:0.027 / U:7.444 seconds]
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