Date: 04 Oct 2001 10:16:38 +0200 From: Dmitry Karasik <dmitry@karasik.eu.org> To: freebsd-stable@freebsd.org Subject: /dev/cuaa broken ? Message-ID: <u4rpfhlax.fsf@karasik.eu.org>
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Hello!
After upgrade to 3.5 to 4.3-stable we encoutered a problem
with our custom device connected to com-port. The device
accepts command strings and returns strings in response,
but under 4.3 it strangely does not respond to commands
that are longer than 15 bytes ( 16 with \r).
The device is controlled by a code, which, if stripped to
functional minimum is as such:
open F, "+< /dev/cuaa0" or die "Cannot:$!\n";
system "/bin/stty -f /dev/cuaa0 gfmt1:ispeed=19200:ospeed=19200 cstopb";
print F "123\r"; # <- works under both 3.5 and 4.3
# print F "1234567890123456\r" # <- doesn't work under 4.3
print "|$_|\n" while <F>;
close F;
One more strange effect is, that under cu(1) it works. That makes
us assume that the programming technique used into our program
is inappropriate - but it seems pretty straightforward and
we are just clueless about what implicit 16-byte buffers
might be involved here. My suspicion is that it's the device driver bug,
but unfortunately we cannot afford tracking the exact commit that caused
the malfunction.
Any help will be appreciated - change to the code, or to the kernel
variables, or whatever. Please help.
--
Sincerely,
Dmitry
--- www.karasik.eu.org ---
Life ain't fair, but the root password helps.
- BOFH
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