Messages in this thread | | | Date | Thu, 15 Dec 2005 13:42:16 -0800 (PST) | Subject | Re: MSI and driver APIs | From | "David S. Miller" <> |
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From: Roland Dreier <rdreier@cisco.com> Date: Thu, 15 Dec 2005 13:18:04 -0800
> Benjamin> I'm tempted to leave them enabled and only disable them > Benjamin> when request_irq() is done on the legacy INTx... Does > Benjamin> anybody see a problem with this approach ? > > You might run into trouble on hardware (think tg3 or its ilk again) > where you might have to do something beyond disabling MSI in the PCI > header to switch the chip out of MSI mode.
I think because of kinds of cases and other issues, going with MSI by default is a non-starter.
Perhaps a better approach is to use a flag in the pci_driver_struct or similar that says "you can have MSI enabled by default". And gradually convert drivers over which we know will handle it properly.
Doing some tom foolery with request_irq() sounds like a half-baked idea at best. The biggest argument against that is that this is not a PCI interface, so expecting it to have PCI side effects is really asking for trouble. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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