Jeff Garzik wrote:I checked the code: IRQ_DISABLE is implemented in software, i.e. handle_level_irq() only calls handle_IRQ_event() [and then the nic irq handler] if IRQ_DISABLE is not set.
I think the scenario you outline is an illustration of the approach's fragility: disable_irq() is a heavy hammer that originated with INTx, and it relies on a chip-specific disable method (kernel/irq/manage.c) that practically guarantees behavior will vary across MSI/INTx/etc.
OTHO: The last trace looks as if nv_do_nic_poll() is interrupted by an irq.
Perhaps something corrupts dev->irq? The irq is requested with
request_irq(np->pci_dev->irq, handler, IRQF_SHARED, dev->name, dev)
and disabled with
disable_irq_lockdep(dev->irq);
Someone around with a MSI capable board? The forcedeth driver does
dev->irq = pci_dev->irq
in nv_probe(), especially before pci_enable_msi().
Does pci_enable_msi() change pci_dev->irq? Then we would disable the wrong interrupt....