On Fri, 13 Oct 2000, Andrew Morton wrote: > > Oct 9 17:29:02 fwintern kernel: eth0: Interrupt posted but not > > delivered -- IRQ blocked by another device? > > This is the infamous APIC bug. I have about ten reports of this over a > four-month period. Mark Hemment mentioned it just yesterday. > > This is not a 3c59x problem. It is due to the APIC forgetting how to > generate interrupts for a particular IRQ. It happens mostly for NICs > because they generate a lot of interrupts. I've had it happen just > once. In that case, _nothing_ would make the interrupt come back > (including a driver unload/reload). > > This gets reported a lot by 3c59x users because this driver specifically > detects and reports on the problem. Hmm, that's interesting. It would be worthwhile to see a dump of APICs' state when this happens -- maybe an EOI message gets lost for some reason or an erratum is biting us. There are functions for such kind of diagnostics already available; they are print_IO_APIC() and print_all_local_APICs() and may be called on demand by a tiny module, for example. Maciej -- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available + - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
