Re: [PATCH] ALSA: hda-intel - Disable MSI support by default

From: Roland Dreier
Date: Wed Nov 15 2006 - 13:46:14 EST


> > Huh? The device can't generate any legacy interrupts once MSI is
> > enabled. As the PCI spec says:
>
> PLEASE.
>
> The spec is just so much toilet paper. The ONLY thing that matters is what
> real hardware does. So please please please PLEASE don't start quoting
> specs as a way to "prove your point". It is totally meaningless.

Sorry, I think you misunderstood. I've certainly seen my share of
crazy devices doing things like endian-reversing the MSI address and
sending interrupt messages off into random space. The only thing I
was disagreeing with was that Jeff suggested it was a driver bug not
to do pci_intx(0) when enabling MSI.

I don't doubt that there are broken devices out there that do generate
wire interrupts even when MSI is enabled. I just don't think we
should go around "fixing" working, correct drivers for devices that
_do_ follow the spec.

- R.
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