Hi
The Serial-HOWTO mentions someone has proposed to patch the serial driver
to work around a flaw in the AMD SC400's internal UART. Because I currently
have to deal with exactly this flaw in an embedded system, I'm now looking
for existing patches [but had no success finding any, neither using search
engines nor in the inofficial patch archives].
I added a check for THRI in IIR (beside the THRE flag in LSR), which seems
to do the job (only the LSR is updated too late), but maybe someone has
another (better tested...) solution that does not add much overhead and
is safe to use with SC400 *and* standard UARTs ?
My solution furthermore uses a flag to make sure that transmit_chars() is not
called twice (1st time because of THRI in IIR, then THRE in LSR) within the
same interrupt. Is this really required to avoid xmit FIFO overflow (I didn't
examine all the counters involved, maybe they already prevent it)?
bibi,
Kolja
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Kolja Waschk <[EMAIL PROTECTED]> iXO mail+news FSB +49-40-8891-3034 fax -3035
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