On 10/16/07, Jeff Garzik <[EMAIL PROTECTED]> wrote: > Yinghai Lu wrote: > > On 10/15/07, Jeff Garzik <[EMAIL PROTECTED]> wrote: > >> Manfred Spraul wrote: > >>> Jeff Garzik wrote: > >>>> 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. > >>>> > >>> 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. > >>> 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.... > >> Remember, fundamentally MSI-X is a one-to-many relationship, when you > >> consider a single PCI device might have multiple vectors. > > > > msi-x is using other entry > > > > if (np->msi_flags & NV_MSI_X_ENABLED) > > > > enable_irq_lockdep(np->msi_x_entry[NV_MSI_X_VECTOR_ALL].vector); > > Correct, but the overall point was that MSI-X conceptually conflicts > with the existing "lockless" disable_irq() schedule, which was written > when there was a one-one relationship between irq, PCI device, and work > to be done.
Can I use your new driver with RHEL 5 or RHEL 5.1? YH - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
