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Bug 9392

Summary: dropped serial bits|bytes
Product: [Retired] Red Hat Linux Reporter: wb8foz
Component: kernelAssignee: Michael K. Johnson <johnsonm>
Status: CLOSED WONTFIX QA Contact:
Severity: low Docs Contact:
Priority: medium    
Version: 6.1   
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2002-12-16 02:52:11 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description wb8foz 2000-02-13 05:25:11 UTC 
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 20:51:30 UTC 
This is a kernel driver problem ...
Comment 2 Alan Cox 2000-08-08 19:35:56 UTC 
Does hdparm -u1 /dev/hda fix this
[See man hdparm first]
Comment 3 wb8foz 2000-08-19 02:13:52 UTC 
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 18:22:28 UTC 
Im suprised you see it with -u1. What other drivers are on your box.
Comment 5 Alan Cox 2002-12-16 02:52:11 UTC 
Ancient release, no reply