Re: serial flow control appears broken

From: Lee Howard
Date: Sat Aug 04 2007 - 20:00:46 EST


Paul Fulghum wrote:

Lee Howard wrote:

And in repeat tests it is quite evident that IDE disk activity is, indeed, at least part of the problem. As IDE disk activity increases an increased amount of data coming in on the serial port goes missing.


Lee, you mentioned 2.2.x kernels did not exhibit this problem.

Was this on the same hardware you are currently testing?


Yes it was... except for the hard drive. I have different installs of different operating systems on different hard drives. I change the hard drive when switching between 2.2.5 and 2.6.5.

Which 2.2.x version were you using?


The default 2.2.5 kernel that comes with RedHat 6.0.

Was the 2.2.x serial driver also identifying the UART as a 16550A?


Yes it does.

Can you get /proc/interrupts output
from both the current setup and the 2.2.x setup?


Current (2.6.5):

CPU0
0: 14660696 XT-PIC timer
1: 8 XT-PIC i8042
2: 0 XT-PIC cascade
3: 1240314 XT-PIC serial
4: 778901 XT-PIC serial
8: 1 XT-PIC rtc
10: 111647 XT-PIC eth0
14: 221202 XT-PIC ide0
15: 34 XT-PIC ide1
NMI: 0
ERR: 5

(2.2.5):

CPU0
0: 5908 XT-PIC timer
1: 88 XT-PIC i8042
2: 0 XT-PIC cascade
8: 2 XT-PIC rtc
10: 38 XT-PIC Intel EtherExpress Pro 10/100 Ethernet
13: 1 XT-PIC fpu
14: 36637 XT-PIC ide0
15: 4 XT-PIC ide1
NMI: 0

Thanks,

Lee.
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