freebsd stable - Jan 2005 - Interrupt load high after 73 minutes uptime with ath(4) hostap

I'm running:
FreeBSD 5.3-STABLE FreeBSD 5.3-STABLE #0: Mon Jan 31 00:54:51 CET 2005
i386

The card is (Netgear WG311T):
ath0: <Atheros 5212> mem 0xe7000000-0xe700ffff irq 9 at device 15.0 on
pci0

After about 73 minutes uptime my PC is busy processing interrupts.
Top shows 90% in IRQ. Everything is slowed down. Earlier kernels
showed same effect.

When the problem appears, I start "ifconfig ath0 down" then
"ifconfig ath0 up" and everything is ok again for a certain
period of time.

Further info:
IRQ 9 is being shared with ACPI (I tried to turn off ACPI, no effect).
Earlier it was shared with my VGA-card, but showed exactly the same
symptoms.

The high interrupt load is not being reported like e.g. an interrupt
storm on lpt. The system is simply slowed down.

Martin

Martin wrote:
> I'm running:
> FreeBSD 5.3-STABLE FreeBSD 5.3-STABLE #0: Mon Jan 31 00:54:51 CET 2005
> i386
> 
> The card is (Netgear WG311T):
> ath0: <Atheros 5212> mem 0xe7000000-0xe700ffff irq 9 at device 15.0
on
> pci0
> 
> After about 73 minutes uptime my PC is busy processing interrupts.
> Top shows 90% in IRQ. Everything is slowed down. Earlier kernels
> showed same effect.
> 
> When the problem appears, I start "ifconfig ath0 down" then
> "ifconfig ath0 up" and everything is ok again for a certain
> period of time.
> 
> Further info:
> IRQ 9 is being shared with ACPI (I tried to turn off ACPI, no effect).
> Earlier it was shared with my VGA-card, but showed exactly the same
> symptoms.
> 
> The high interrupt load is not being reported like e.g. an interrupt
> storm on lpt. The system is simply slowed down.
This is a known problem in the ath driver in stable that should be fixed 
in current.  I expect you are operating 11g.  Unfortunately backporting 
the necessary changes is very hard and not something I intend to do.

	Sam