[Techtalk] Interrupt disabled

[David Sumbler]

Can anyone shed any light on this?

This evening, while working (ahem!) on the computer, I suddenly got a
message on the screen saying that IRQ 4 was being disabled.

The end of dmesg output shows:

irq 4: nobody cared (try booting with the "irqpoll" option.
 [<c013c9ac>] __report_bad_irq+0x2b/0x6b
 [<c013ca73>] note_interrupt+0x6b/0x90
 [<c013c03e>] __do_IRQ+0x19f/0x221
 [<c0104c98>] do_IRQ+0x5e/0x7a
 =======================
 [<c01034de>] common_interrupt+0x1a/0x20
 [<c0236bcd>] serial_out+0x4b/0x4e
 [<c0238acb>] serial8250_shutdown+0x110/0x175
 [<c0233aa5>] uart_shutdown+0xfe/0x135
 [<c0235383>] uart_close+0x195/0x218
 [<c0214294>] release_dev+0x1ff/0x801
 [<c021268b>] tty_ldisc_ref_wait+0xd/0x97
 [<c0219e2e>] set_termios+0xe4/0xf0
 [<c0117754>] __wake_up+0x6e/0xca
 [<c02127f3>] tty_ldisc_deref+0xc8/0x139
 [<c0215ca5>] tty_ioctl+0x48d/0x498
 [<c0214dc7>] tty_release+0x7/0xa
 [<c015f741>] __fput+0x4e/0xe7
 [<c015e294>] filp_close+0x59/0x5f
 [<c010336f>] syscall_call+0x7/0xb
handlers:
[<c0237da3>] (serial8250_interrupt+0x0/0x215)
Disabling IRQ #4

Looking at /proc/interrupts I see that IRQ 4 is assigned to "serial".
The only thing I have connected to a serial port is a lead that I use
to connect occasionally to my Psion 5mx hand-held computer.  It was
not connected at the time, although the lead was still plugged into
the computer.

What might have caused this event?

David

-- 

David Sumbler