Complete freeze in 2.0.29

Philippe Troin (
Thu, 06 Mar 1997 00:21:00 -0800

[I'm not subscribed to this list, so please Cc: me when answering.
[Cc'ed to the floppy.c and serial.c maintainers]

Here's the story:
Linux tantale 2.0.29 #1 Thu Feb 20 22:18:34 PST 1997 i486 unknown

I've noticed that my machine crashed when I used the floppy disks for
a long time. Crash means complete freeze (no helpful error messages,
no ooopses).
I've narrowed down the problem, and this is how I reproduce it:
1) Start some kind of floppy access, eg a format,
2) Make one of your serial ports transmit fast (I do a ftp for
example through PPP).
On my 66Mhz 486, I've got a freeze within 10 seconds.

This is what I've tried:
1) Put both serial.o and floppy.o in the kernel (were modules)
2) Don't use setserial
3) Don't use irqtune
Without success, the freeze still happens.

I've tried to look into serial.c and added the debug flag
SERIAL_DEBUG_INTR, but then I cannot get any freeze.
I suspect this is an interrupt problem, and that the various printk()
make the top interrupt routine too long to cause the problem.

I have no idea if this a floppy.c or serial.c problem.

FYI, I'm running the serial all day long, and it's quite active
(permanent PP link). I had uptimes of several weeks. The problem only
occurs when both serial _and_ floppy are simultaneously active.

Can anyone reproduce it ?
Better though, any idea of where to look ?