Old topic (sorry): hdparm and lost chars on serial ports

Alan Watson (AlanWatson@flysaa.com)
Wed, 24 Nov 1999 18:28:24 +0200


Hi

Sorry to return to a topic much discussed about a
month ago, but I remain mystified. What precisely
is the conflict between IDE access and the serial
ports?

I gathered that if one changes some or other micro-
second "wait" in the IDE drivers, then the serial
port doesn't get polled often/fast enough to reap all
the data being sent it. And I also understand it
only happens in PIO mode, not DMA mode? And then
only on a few broken IDE controllers (and you don't
know if you've got one till you try it out, with
disasterous consequences...)

What is the benefit of tweaking the hd parameters
in the way suggested (how much performance does one
really gain - is it worth the danger for the average
user)?

Can someone who really knows about this conflict
please explain in detail?

Thank you

Alan Watson

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