Bug 9392 - dropped serial bits|bytes
dropped serial bits|bytes
Product: Red Hat Linux
Classification: Retired
Component: kernel (Show other bugs)
i386 Linux
medium Severity low
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Assigned To: Michael K. Johnson
Depends On:
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Reported: 2000-02-13 00:25 EST by wb8foz
Modified: 2008-05-01 11:37 EDT (History)
0 users

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Fixed In Version:
Doc Type: Bug Fix
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Last Closed: 2002-12-15 21:52:11 EST
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Description wb8foz 2000-02-13 00:25:11 EST
Tomcat III
I have 2 mb serial ports, as well as two AST 4-port cards. These often
monitor router console screens; i.e. VT100 emulation w/miniterm.

All the ports have, over time, dropped a bit|byte here & there, as seen
by scrambled screen displays. A ^L-stype screen repaint clears same.

But with 6.1, the problem is visibly worse -- now, in only 15 minutes
or so, the display is a real mess. This seems true more on the 4-ports
than the 2 integral ports, but still ttyS0|1 are worse than in the past.

I checked with Ted Tso & he had no immediate answers.
Comment 1 Jeff Johnson 2000-07-27 16:51:30 EDT
This is a kernel driver problem ...
Comment 2 Alan Cox 2000-08-08 15:35:56 EDT
Does hdparm -u1 /dev/hda fix this
[See man hdparm first]
Comment 3 wb8foz 2000-08-18 22:13:52 EDT
Fog lifts slightly. Looks like 6.1 upgrade (now 2.2.12-20) put IDE drives in PIO
mode. That likely explains why it got so much worse at that time. 

But note the problem exist[s,ed] (to a far lesser extent) even without being
dumped in PIO. Would think 16550A's & 950's had enough buffer.

Comment 4 Alan Cox 2000-09-15 14:22:28 EDT
Im suprised you see it with -u1. What other drivers are on your box.
Comment 5 Alan Cox 2002-12-15 21:52:11 EST
Ancient release, no reply

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