Re: Quad card shares same irq on all ports, but only the first works
Donald Becker <[email protected]>
| Newsgroups | gmane.linux.drivers.tulip.general |
|---|---|
| Message-ID | <[email protected]> |
On Thu, 1 Aug 2002, Alexander Haväng wrote: > We have a problem with quad cards on a specific motherboard where all the > ports are assigned the same irq. > This should be fine, but on all other motherboards we've tried, each > port gets its own irq, when available. Errrmm, please clarify: is the _reported_ IRQ the same, or the _actual_ IRQ. There is a very common bug on x86 motherboards where the reported IRQ on ports 2-4 is wrong. The actual IRQ routing is the IRQ of the first port. [[ The specific bug is in the IRQ assignment for cards behind PCI bus bridges. It's common because all BIOSes use the same PCI IRQ assignment code that Intel wrote eight years ago. ]] > Now, here comes the weird part. Only when packets arrive on the first > port interupts are actually raised. So if the first port is not > receiving any packets, neither will the other ones. Yup, that's the mostly-harmless symptom. The bad symptom is when you have some other device on the same IRQ, and port 2-4 is active. An interrupt is raised from the NIC and there is no way to clear it, so the kernel loops in the interrupt handler dispatch. Doh! > We're using a 21143 quad card from Phobos, and have also tried the > DLink DFE-570TX card, with the same results. What driver version? (It's likely not my release...) -- Donald Becker [email protected] Scyld Computing Corporation http://www.scyld.com 410 Severn Ave. Suite 210 Second Generation Beowulf Clusters Annapolis MD 21403 410-990-9993 _______________________________________________ tulip mailing list, [email protected] To change to digest mode or unsubscribe visit http://www.scyld.com/mailman/listinfo/tulip