From: almesber@nessie.cs.id.ethz.ch (Werner Almesberger) Subject: Re: Floppy patches (experimental) Date: Fri, 29 May 1992 09:56:01 GMT
In article <1992May26.101438@tioga.ucsc.edu> sinster@scintilla.capitola.ca.us writes:
> Before you patch the kernel to fix this problem, I suggest you check your
> termination packs on your floppies... If they're not correct, then you'll
> experience the problem above.
Hmm ... does incorrect termination only break the media changed signal or
does it break drive selection (and possibly many other things too) ? If
it's only the media changed line, then bad termination may indeed be the
reason why people see this problem.
I haven't received any feedback on my patch yet, so I suspect that nobody
has tried it yet. Could somebody who has experienced any of the following
problems please apply it and tell me whether it helps or not ?
1) Problem: Floppy X is mounted and data is written to it. Floppy X is
unmounted and replaced by floppy Y (in the same physical drive). Now,
floppy Y appears to contain a partial copy of the data of X.
Diagnosis: The media changed line doesn't seem to work on some drives.
Therefore, the kernel doesn't know when to flush its caches and
carries cached data to the new media.
Fix: My patch adds a possibility to (manually) tell the floppy driver
that a media change has occurred. (See my previous posting in this
thread.)
2) Problem: 360kB ("PC") drives are unusable with 0.96 kernels.
Diagnosis: this might be caused by an invalid signal on the media
changed line. (Old drives use that line to indicate whether the
drive is ready. They don't have a media change detection.)
Fix: The patch disables automatic media change detection for 360kB
drives. The command setfdprm -d /dev/whatever has to be issued when
the disk is changed.
The patch is on banjo.concert.net in pub/Linux/Incoming/fd-misc.tar.Z
- Werner
-- _________________________________________________________________________ / Werner Almesberger, ETH Zuerich, CH almesber@nessie.cs.id.ethz.ch / / IFW A44 Tel. +41 1 254 7213 almesberger@rzvax.ethz.ch / /_BITNET:_ALMESBER@CZHETH5A__HEPNET/CHADNET:_[20579::]57414::ALMESBERGER_/