Messages in this thread | | | From | Stephen Hemminger <> | Subject | Re: [PATCH] ALSA: hda-intel - Disable MSI support by default | Date | Wed, 15 Nov 2006 11:09:53 -0800 |
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On Tue, 14 Nov 2006 23:24:04 -0500 Jeff Garzik <jeff@garzik.org> wrote:
> David Miller wrote: > > Is this absolutely true? I've never been sure about this point, and I > > was rather convinced after reading various documents that once you > > program up the MSI registers to start generating MSI this implicitly > > disabled INTX and this was even in the PCI specification. > > > > It would be great to get a definitive answer on this. > > > > If it is mandatory, perhaps the driver shouldn't be doing it and > > rather the PCI layer MSI enabling should.
pci_enable_msi() calls msi_capability_init() and that disables intx already.
> > I can't answer for the spec, but at least two independent device vendors > recommended to write an MSI driver that way (disable intx, enable msi). > > Completely independent of MSI though, a PCI 2.2 compliant driver should > be nice and disable intx on exit, just to avoid any potential interrupt > hassles after driver unload. And of course be aware that it might need > to enable intx upon entry. > > Jeff
The driver shouldn't deal with this, pci_disable_msi() does.
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